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PRINCIPLES AND PRACTICE 



BUTTER-MAKING 



A TREATISE ON THE CHEMICAL AND PHYSICAL PROPERTIES 

OF MILK AND ITS COMPONENTS 

THE HANDLING OF MILK AND CREAM, AND THE 

MANUFACTURE OF BUTTER THEREFROM 



G. L. McKAY AND C. LAKSEI^T, M.S. A. 

Professor in Dairying Assistant Professor in Dairying 

OF THE Iowa State College, Ames, Ia. 



FIB8T EDITION 
PIKST THOUSAND 



NEW YORK 

JOHN WILEY & SONS 

LoNDOiT: CHAPMAN & HALL, Limited 

1906 



</v 



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f) 



^ 





LIBRARY of CONGRESS 






Two CoDies Received 






UAN 13 1906 






f. Copyrijht Entry 




i 


CLASS ex. XXc. No, 
COPY B. 




Copyright, 1906 


BY 


G. L. 


McKAY AND C. LAKE 


3 EN 



^' 



x^ 



(X 







IP 



ROBERT DRUMMOND, PRINTER, NEW TORE 



PREFACE. 



The science and practice of Dairying is constantly broadening. 
The different phases of this industry cannot now be mastered in so 
short a time as years ago, when eomparatively little was known 
about the principles upon which dairying is now securely based. 

In connection with the teacliing of dairying in the special 
four-year course at the Iowa State College, a set of lectures on 
advanced butter-making was prepared. In compiling these 
lectures special endeavors were exerted toward embodying the 
principles of butter-making, as well as the best practice of this 
art, in this as well as in foreign countries. 

The authors have studied, by personal observation and 
practice, the best and most progressive methods employed in 
butter-making in the principal dairy countries of the world, and 
have endeavored to incorporate these in this work. In con- 
nection with this practical phase of the question, the authors 
have endeavored to give such related scientific information as 
may be of interest and value. The general scientific knowledge 
has been absorbed from time to time from work done by various 
investigators at the different Experiment Stations. To all of 
these men w^ho have searched for and discovered facts bearing 
upon dairying, the authors wish to express thanks and acknowl- 
edgment. 

The statistics and tables given in this work have been quoted 
from noted reliable authorities as indicated. 

The authors believe that the subject of dairying should no 



IV PREFACE. 

longer be treated as one whole. For this reason such subjects 
as Testing Milk and its Products, Dairy Bacteriology, Cheese- 
making, and Technology of Milk and its Products, have not been 
treated comprehensively in this work. 

These lectures have been used, modified and changed, and 
under preparation for several years. At the present time the 
writers believe they are in such a condition as to warrant the 
publication of them. 

The authors admit that in our present state of knowledge it 
is in some instances difficult to distinguish well-established facts 
from those not so universally confirmed. It has been the object 
of the writers to give such information as is supported by the 
preponderance of experimental evidence. 

The authors are also indebted to the following parties for 
the use of electrotypes : Mower-Harwood Co., and Cherry Bros., 
Cedar Rapids, la.; Creamery Package Co., Waterloo Cream Sep. 
Co., and Iowa Separator Co., Waterloo, la.; Vermont Farm 
Machine Co., BeUows Fafis, Vt.; Jensen Mfg. Co., Topeka, 
Kans.; Ox Fiber Brush Co., National Creamery Supply Co., 
International Harvester Co., Davis Cream Sep. Co., Borden & 
Selleck Co., and De Laval Sep. Co., Chicago, 111.; Wagner Glass 
Works, and J. H. Monrad, New York, N. Y.; Burrell & Co., 
Little Falls, N. Y.; Empire Cream Sep. Co., Bloomfield, N. J.; 
Dairy Queen Mfg. Co., Flora, Ind.; Dairy Record, St. Paul, Minn., 
and W. D. Hoard, Ft. Atkinson, Wis. 

G. L. McKay, 
C. Larsen. 

Iowa State College, Dairy Department. 



CONTENTS. 



CHAPTER I. 

PAGE 

Composition op Milk 1 

1. Definition of Milk 1 

2. Composition of Milk 2 

3. Variation of Total Solids 3 

4. Water 4 

5. Fat in Milk 5 

6. Properties of Fat 7 

7. Glj'cerides of Fat 8 

8. Theories in Regard to Films Enveloping Fat -globules 9 

9. Classes of Fats • 10 

A. Volatile - H 

B. Non-volatile 12 

10. Composition of Butter-fat • 13 

11. Casein 15 

12. Albumen • 16 

13. Sugar 16 

, 14. Ash •••••• 18 

\ 15. Gases or Taints of Milk 18 

^ 16 Coloring Matter 20 

17. Other Constituents of Milk 20 



CHAPTER II. 

Milk Secretion 22 

1. Mammary Gland as a Secretory Organ 22 

2. Internal Structure of Cow's Udder 22 

3. Theories of Milk Secretion 2.5 

4. Conditions Affecting Secretion of Milk 28 

5. External Appearance of Udder 29 

6. Milk-fever 30 

V 



•VI CONTENTS. 

CHAPTER III. 

PAGE 

Properties of Milk 31 

1. Color 31 

2. Flavor 31 

3 Opacity of Milk ; 31 

4. Chemical Reaction of Milk 32 

5. Specific Gravity of Milk 32 

6. Natural Separation of Milk and Cream 35 

7. Adhesion of Milk 37 

8. Viscosity of Milk 37 

9. Specific Heat of Milk 38 

10. Effect of High Heat on Properties of Milk 38 

A. Destroys nearly all Germs 39 

B. Diminishes Viscosity or Body 39 

C. Drives off Gases 40 

D. Imparts a Cooked Taste 40 

E. Precipitates Albuminoid and Ash Contents 41 

F. Destroys Properties of Enzymes 41 

G. Divides the Fat-globules 42 

H. Caramelizes the Sugar 42 

I. General Remarks 43 

CHAPTER IV. 

Ferments in Milk 44 

1. Definition 44 

2. Size and Shape of Bacteria 45 

3. Favorable Conditions for Bacterial Growth 45 

A. Food 45 

B. Temperature 46 

C. Moisture 47 

4. Unfavorable Conditions for Bacterial Growth 48 

5. Kind of Germ Found in Milk 49 

6. Number of Bacteria in Milk 51 

7. Sources of Bacteria in Milk 52 

8. Effect of Thunder-storms on Souring Milk 53 

CHAPTER V. 

Abnormal Milk 54 

1. Colostrum Milk 54 

2. Salty Milk , 55 

3. Bloody or Red Milk 56 

4 Blue Milk 57 



CONTENTS. VU 

PAGE 

5. Yellow Milk 57 

6. Ropy Milk 58 

7. Bitter Milk 58 

8. Milk from Cows which have been in Milk a Long Period 60 

9. Milk from Spayed Cows 61 

10. Milk from Sick Cows 62 

CHAPTER VI. 

Variation of Fat in Milk 65 

1. Individuality of Cows 65 

2. Breed of Cows 67 

3. Time between Milkings 68 

4. Manner of Milking 70 

5. Milking-machines 70 

6. Fore Milk and After Milk 73 

7. Age of Cow 74 

8. Lactation Period 74 

9. Food of Cows 75 

10. Environmental Conditions 76 

CHAPTER VII. 

Receiving, Sampling, and Grading Milk and Cream 77 

1. Receiving and Grading of Milk and Cream 77 

A. Detection of Abnormal Milk Through the Senses 79 

B. Use of Acid Tests 80 

C. Use of Fermentation Tests 81 

a. Gerber and Wisconsin Curd Tests 81 

D. Grading Milk by Heating 82 

E. Use of Babcock Test and Lactometer 84 

2. Necessity of Good Milk 89 

3. Sampling of Milk 93 

4. Sampling-tube 94 

5. Sampling Churned Milk 96 

6. Frozen Milk 96 

7. Sour and Coagulated Milk 97 

8. Apportioning Skimmed Milk 97 

CHAPTER VIII. 

Composite Samples 99 

1. Definition 99 

2. When to Sample 99 



viii CONTENTS. 

PAGE 

3. Kind of Preservatives to Add 99 

4. Arrangement of Composite Samples 102 

5. Care of Composite Samples 102 

6. Average Samples 104 

7. Composite Sampling without the Use of Preservatives 104 

CHAPTER IX. 

Creamery Calculation 105 

1. Finding Average Percentage of Fat 1 05 

2. Calculation of Overrun 107 

A. Thoroughness of Skimming 108 

B. Completeness of Churning 108 

C. General Losses in Creameries 108 

D. ComiDosition of Butter Manufactured 108 

3. Calculation of Churn-yield 109 

4. Calculation of Dividends 109 

5. Cream-raising Coefficient. . . .- 113 

6. Statement to Patrons 113 

7. Paying for Fat in Cream as Compared with Paying for Fat in Milk 116 

8. Degree of Justice in Paying Cream Patrons More per Pound of 

Fat than the Milk Patrons 117 



CHAPTER X. 

Heating Milk Previous to Skimming 118 

1. Reasons for Heating 118 

2. Advantages of Warming Milk to High Heat Previous to Skim- 

ming 1 19 

3. How Heated : 121 



CHAPTER XI. 

Separation of Cream 123 

1. Gravity Creaming. 123 

A. Shallow-pan System 123 

B. Deep-setting System 124 

a. Probable Explanation 126 

C. Water-dilution Cream (HydrauHc) 128 

2. Centrifugal Creaming 129 

A. Advantages 129 

B. History of Centrifugal Separators 130 

C. Modern Separators 132 

D. Classification of Separators 133 



CONTENTS. - IX 

PAGE 

E. Process of Separation 134 

F. Relative Amount and Richness of Milk and Cream 

Obtained 137 

a. Regulation of the Cream or Skimmed-milk Screw. . 137 

h. Rate of Inflow l38 

c. Speed 138 

d. Temperature 139 

G. Conditions Affecting Efficienc}- of Separators 139 

a. Manner of Heating Milk 139 

b. Condition of the Milk 141 

c. Overfeeding the Separator 141 

d. Speed 142 

e. Steadiness in Running 143 

/. Thickness of Cream 144 

g. Slush in Bowl 144 

h. General Remarks 145 

CHAPTER XII. 

Farm Separators 146 

1. Introduction of Farm Separators 146 

2. Reasons for Introducing Farm Separators 147 

3. Objections to Farm Separators 152 

4. Thickness of Cream 152 

5. Power for Farm Separators 155 

6. Care of Cream on the Farm 158 

7. Disposition of Cream 167 

A. Shipping of Cream 169 

B. Making Butter on the Farm 169 

CHAPTER XIII. 

Pasteurization 173 

1. Definition 173 

2. Methods of Pasteurization 173 

A. Intermittent 173 

B. Continuous 174 

3. Selection of Pasteurizers 175 

A. Durability and Capacity 175 

B. Economic Efficiency 175 

a. Heating Surface 176 

b. Degree of Adhesiveness 177 

c. Thickness of Layer of Condensed Steam 180 

d. DifTerence in Temperature on Each Side of Heat- 

ing Surface 181 



X CONTENTS. 

PAGE 

e. Proper Utilization of Steam Turned into the Pas- 
teurizer 182 

C. The Cost of Pasteurization 183 

D. Advancement of Pasteurization 183 

E. Advantages of Pasteurization 184 

F. Disadvantages of Pasteurization 186 

CHAPTER XIV. 

Cream-ripening 187 

1. Definition 187 

2. Objects of Cream-ripening 187 

A. Production of Flavor and Aroma 187 

B. Increases the Churnability of Cream 191 

C. Increases the Keeping Quality of Butter 192 

3. Ripening Temperature of Cream 194 

4. Amount of Starter to Add to Cream 196 

5. Stirring of Cream during Ripening 197 

6. Natural Ripening 198 

7. Artificial Ripening 199 

8. Ripening Cream when Churning is Done Everj^ Other Day 201 

9. Mixing of Cream 202 

A. Quality of Cream 203 

B. Kind of Market 204 

C. Amount of Cream 204 

D. General Creamery Conditions 205 

10. Examining and Testing Cream for Acidity during Ripening. . . . 205 

11. Mann's Test 206 

12. Farrington's Test 208 

13. Amount of Acid to Develop 208 

14. Changes in Cream 210 

A. Physical 210 

B. Biological 210 

C. Chemical 211 

CHAPTER XV. 

Starters 216 

1. Definition 216 

2. History 216 

3. Classification of Starters 216 

4. Preparation of Natural Starters 217 

5. Commercial Starters or Pure Cultures 217 

6. Preparation of Commercial Starters 218 

7. Inoculation 220 



CONTENTS. xi 

PAGE 

8. Length of Time a Starter Can be Carried 222 

9. Poor Starters 223 

10. Under-ripening and Over-ripening of Starters 223 

11. Amount of Starter to Use 224 

12. Use of Starter-cans 225 

CHAPTER XVI. 

Churning and Washing Butter 226 

1. Definition ' 226 

2. Conditions Affecting the Churnability of Cream 227 

A. Temperature 227 

B. Richness of Cream 231 

C. Amount of Cream in Churn 233 

D. Degree of Ripeness 234 

E. Nature of Agitation 235 

F. Size of Fat-globules 236 

3. Straining of Cream 238 

4. Color 238 

5. When to Stop the Churning Process 239 

6. Churning Mixed, Sweet, and Sour Cream 243 

7. Difficult Churning 243 

8. Keeping Churn in Sweet Condition 245 

9. Washing of Butter 247 

A. Purpose of Washing 247 

B. Temperature of Wash-water 247 

C. Kind of Wash-water to Use 248 

10. Methods of Purifying Wash-water 250 

A. Filtration 250 

a. Continuous 253 

b. Intermittent 254 

B. Pasteurization 250 

11. Ad^•antages of Purification of Wash-water 255 

CHAPTER XVII. 

Salting and Working of Butter 256 

1. Amount of Salt to Use to Produce Proper Flavor 256 

2. Effects of Salt upon Keeping Properties 258 

3. Salt Facilitates the Removal of Buttermilk 259 

4. Salt in Relation to Water in Butter 259 

5. Gritty Butter 263 

6. Mottled Butter 263 

7. Brine-salting 264 

8. Objects of Working Butter 266 



xii CONTENTS 

CHAPTER XVIIl. 

PAGE 

Packing and Marketing Butter 269 

1. Kind of Package to Use 269 

2. Preparation of Tubs 271 

3. Packing of Butter 273 

4. Packing Butter for Exhibition Purposes 275 

5. Storing Butter in Creameries 276 

6. Cost of Producing One Pound of Butter 278 

CHAPTER XIX. 

Composition of Butter 281 

1. Average Composition 281 

2. Effect of Composition of Butter on Quality 281 

A. Curd and Sugar 282 

B. Salt 282 

C. Water 2<S3 

D. Fat 286 

CHAPTER XX. 

Judging and Grading Butter 287 

1. Standard for Judging 287 

2. Manner of Judging 290 

A. Bod}' 290 

B. Flavor 290 

C. Color 291 

D. Salt 292 

E. Style 292 

3. Classification of Butter 292 

4. Grades of Butter 293 

5. Export Butter 296 

APPENDIX. 

I. A Laboratory Course in Farm Dairying Consisting of Four- 
teen Exercises on Handling, Separating, and Testing 
Milk and Cream under Farm Conditions. A Few of the 
Exercises are Devoted to the >Ianufacture of Butter on 

A Small Scale 299 

II. Legal Standards for IMilk — Dairy Laws 314 

III. Metric System of Weights and Measures with Tables for 
Converting them into Customary LTnited States Equiv- 
alents AND THE Reverse 3J5 



BUTTER-MAKING. 



CHAPTER I. 
COMPOSITION OF MILK. 

Definition. — Normal milk is a liquid secreted in special 
glands of all females belonging to the mammalian group. It 
is composed chiefly of water, proteids, fats, sugar, and minerals. 
Coloring-matters and gases and some organic acids are found 
in small quantities. 

All normal milk from the different classes of animals, such 
as mare, bufTalo, goat, ewe, ass, and cow, has a general resem- 
blance in that it all contains water, fat, proteids, sugar, and 
ash. But milk from different animals varies in the relative 
proportions of its constituents. The chemical and physical 
properties are not alike. Human milk, when treated with 
half its volume of ammonium hydrate and the mixture kept 
at a temperature of 60° centigrade for about twenty minutes, 
assumes an intense red color. Cow's milk turns faintly yellow 
if treated in the same way. This test was reported by Unikoff, 
of St. Petersburg, at the meeting of the Medical Section, Royal 
Academy of Medicine, in Ireland. The various kinds of milk 
also differ from each other in their behavior towards rennet. 
Richmond has divided milk into two classes: Class I includes 
milk from the ewe, buffalo, goat, and cow. When rennet is 
added to the milk from these animals, the casein coagulates into 
a firm curd. Class II includes human milk, milk of the ass 
and mare. ^\lien rennet is added to the milk of these animals, 
a soft curd or none at all is formed. The latter class seems 



2 BUTTER-MAKING. 

to include the animals without horns, while the first includes 
those with horns. 

As the cow's milk is used chiefly as a food, it has been 
subjected to more extended and more careful investigation 
than the milk of other animals, and, as a consequence, more 
definite knowledge has been obtained concerning its com- 
position, properties, and uses. The succeeding discussions 
have reference to cow's milk, if not otherwise stated. 

Composition of Milk. — It is impossible to get accurate 
figures on the composition of milk, as each of the milk con- 
stituents is subject to fluctuation from various conditions, 
such as individuality of cow, breed, season of the year, lacta- 
tion period, milking, and environment. 

The average composition, as determined by 200,000 analyses 
reported by Richmond as follows: 

Water 87.10 

Fat 3.90 

Milk-sugar 4. 75 

_^ . ., f Casein 3 

Proteids i .„ , 

[ Albumen 4 

Ash 75 

The composition of various kinds of milk is given by Konig 
as follows : 





No. of 
Analy- 
ses. 


Water. 


Fat. 


Casein 

and 

Albumen. 


Milk- 
sugar. 


Ash. 


Specific 

Gravity. 


Human 


107 

50 

8 

7 

793 

32 

38 

8 

28 

3 

1 

3 

3 


87.41 
90.78 
82.25 
89.64 
87.17 
80.82 
85.71 
84.04 
75.44 
79.30 
90.43 
86.57 
86.55 


3.78 
1.21 
7.51 
1.64 
3.69 
6.86 
4.78 
4.55 
9.57 
9.10 
4.51 
3.07 
3.15 


2.29 
1.99 
5.05 
2 22 
3'55 
6.52 
4.29 
7.23 
11.17 
2.51 

"4"" 
3.90 


6.21 
5.67 
4.44 
5.99 
4.88 
4.91 
4.46 
3.23 
3.09 
8.. 59 
4.40 
5.59 
5.60 


.31 
.35 

.75 
.51 
.71 
.89 
.76 
1.05 
.73 
.50 
.11 
.77 
.80 


1.0270 


Mare 


1.0347 


Buffalo 


1.0350 




1.0345 


Cow 


1.0316 


Ewe 


1.0341 


Goat 


1.0328 


Sow 


1.038 


Bitch 


1.035 


Elephant 

Hippopotamus. . . 
Camel 


1.0313 
1.042 


Llama 


1.034 







COMPOSITION OF MILK. 3 

Variation of Total Solids. — As applied to milk, "Total 
Solids," is a term that includes fat, casein, albumen, sugar, 
and ash; in other words, all the milk constituents except the 
water. "Sohds Not Fat" is a term often used, and includes 
the casein, albumen, sugar, and ash, or all the milk constituents 
except water and fat. " Serum " is a term used to designate all the 
milk constituents except the fat. The fat is the most valuable 
constituent of the total solids. The variation in the total 
solids of milk during the summer months is shown in the table 
quoted below from Dr. Van Slyke of Geneva, New York: 

TiT„„+i, Per Cent Per Cent of 

^^°°*'^- of Water. Total Solids. 

May 87.44 12.56 

June 87.31 12.69 

July 87.52 12.48 

August 87.37 12.63 

September 87 13 

October 86.55 13.45 

Dr. Van Slyke also studied the effect of the lactation period 
upon the total solids in milk. A herd of fifty cows, calving 
in different months of the year, was used in the experiment. 
The per cent of total solids of this herd seems to average a 
little high all through the ten months. The total solids were 
found to be 14% during the first month, decreasing to 13.47% 
during the next two months, then gradually increasing with the 
advance of the lactation period. In the tenth month the average 
total solids was 14.83%. Pingree, of Pennsylvania, reports 
having found normal milk from a cow, which contained 17.01% 
total solids. Sherman * reports a very high average total of 
the milk solids. He treated the milk from thirteen cows, 
and found it to contain on an average 18.03% of total sohds. 
Konig reports a minimum of total solids of 9.31%, a maximum 
of 19.68%, and an average of 12.83%. The average total 
solids quoted above from Richmond is 12.90%, which agrees 
closely with Konig's results. 

* Journ. Am. Chem. Soc. 



4 BUTTER-MAKING. 

The difference in total solids of milk from some of the 
leading breeds has also been studied by Dr. Van iSlyke, and 
the results are as follows: 

T, , Per Cent Per Cent of 

^■■^•'"- of Water. Total Solids. 

Holstein 88.20 11.80 

Ayrshire 87.25 12.75 

Shorthorn 85.70 14,30 

Devon 85.50 14.50 

Guernsey 85.10 14.90 

Jersey 84.60 15.40 

The maximum and minimum amounts of total solids men- 
tioned above are abnormal cases. The normal variations of 
the solids in milk are within comparatively narrow liixdts. 
For this reason the minimum standard for total milk solids, 
in states where dairy laws are in force, is fixed by law. Usually 
12% is the minimum. 

Water. — From what has been said above concerning the 
total milk solids, it will be seen that water constitutes by far 
the largest portion of milk. It is quite uniform, and in milk 
from a mixed herd the water seldom falls below 86% and 
seldom exceeds 88%. Variations ranging from a Httle less 
than 80% to a trifle over 90% are on record. But such varia- 
tions nmst be looked upon as occurring in only a very few special 
cases. 

It has often been asserted that cows in the spring of the 
year, when they are pasturing on new grass, or feeding on other 
succulent foods, yield milk which contains an excess of water. 
Under such conditions there is a tendency for cows to pro- 
duce milk with a water content a trifle higher, as has already 
been shown by the figures quoted from Dr Van Slyke. As a 
rule this is much overestimated. It is even a common occur- 
rence to hear creamery operators say that their "soft" or 
"slushy" butter, in the early spring, is due to the excess of the 
water present in the milk. Tliis particular phase will be dis- 
cussed further under the heading of "Fats in Milk." 

The question has often been raised: Is the water in milk 



COMPOSITION OF MILK. 5 

the same, or any more valuable than water obtained from 
other natural sources? The water in milk, so far as known, is 
transuded from the blood-vessels in the udder into the milk 
glands. It is so perfectly mixed with the other milk con- 
stituents, and holds the milk sohds in such perfect emulsion 
and solution that it would seemingly be impossible to prepare 
milk so perfectly by artificial means. However, a substance 
is prepared by Jacob C. Van Marken, Neuweid, Germany, 
which, \\hen added to water, produces a substance similar in 
appearance to watered skimmed milk. The preparation is 
named ''Kalberrahm Vita." The first name literally means 
calf-cream. It has a syrupy consistency, and in appearance 
resembles light-brownish molasses. It is sold in tin cans, and 
recommended highly for calf-feeding when mixed with skimmed 
milk. A^Tien mixed with water, it is recommended highly for 
hog-feeding. 

Water distilled from milk has the same appearance as ordi- 
nary distilled water. It is clear and colorless. The chemical 
reaction when phenolphthalein is used as an indicator, is neutral, 
the same as that of ordinary distilled water, even when dis- 
tilled from milk in which acid has developed. But there is 
a considerable difference in the taste and smell. This indi- 
cates that some of the volatile substances are distilled over with 
the water. The probabihty is that these flavoring substances 
are so closely associated with water in milk that they are in- 
separable, and that the only place where this water can be 
prepared so as to assume these qualities is in the cow's udder. 
The conclusion would then be that the water in normal cow's 
milk cannot be distilled and substituted again by natural 
water and the product retain its normal good flavor. 

Fat in Milk. 

This is by far the most important constituent of milk, 
especially to creamery operators. It exists in the milk in sus- 
pension, in the form of globules so small as to be invisible 
to the naked eye. According to the best authorities, fat- 



BUTTER-MAKING. 



globules, at ordinary living-room temperature, are present in 
milk in a liquid form. Cooling the milk to a very low tem- 









a. 


Skim milk 










o o "J 


o 


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Fig. 1. — Microscopical appearance of different kinds of milk. Magnified 
300 times. (U. S. Fanners' Bui. No. 12.) 

perature (about 50° F.) hardens them. When the globules are 
caused to unite, as in churning, they also solidify. 

The size of the fat-globules is very minute, and varies con- 



COMPOSITION OF MILK. 7 

siderably, according to breeds, individual cows, and the stage 
in the lactation period. The globules in the milk from the same 
cow also vary a great deal. Lloyd found that fat-globules in 
Jersey milk to be from 8 to 12 micro-millimeters in diameter. 
Very few were less than 4 micro-millimeters (a micro-milli- 
meter is t/oo- milhmeter, or ag-Toir of an inch). The majority 
of the fat-globules in milk from Shorthorn cows measured from 
6 to 8 micro-millimeters in diameter. According to Fleisch- 
mann, the size of fat-globules varies between 1.6 micro-milli- 
meters and 10 micro-millimeters in diameter. A Danish in- 
vestigator maintains that the diameter of fat-globules is 
between .0063 and .00014 millimeters, and that 1 cubic centi- 
meter of milk contains from 2.6 to 11.7 million globules. He 
also asserts that a reflection of the light renders it very difficult 
to get the proper size of the fat-globules, as the light tends to 
make the globules appear larger than they are in reahty. 

It has been maintained by some that the larger fat-globules 
contain fats which are different from those contained in the 
smaller globules. But this is by some investigators considered 
to be a matter of conjecture. Most authorities now believe 
that there is no difference in the kinds of fat of the different- 
sized globules, even though some experiments * show that fat 
composed of larger globules has a finer flavor, and a little more 
oily appearance. 

From what has been said, it will be seen that the minute- 
ness of the fat-globules is almost inconceivable. They were 
first discovered in 1697 by A. von Leeuw^enhoek. The minute 
state of division, or the form of emulsion in which they exist 
in milk, renders it easy to digest when consumed as a food. 

Properties of Fat. — The specific gravity of pure butter-fat 
at 15° centigrade is .93002. The refractive index of butter- 
fat at 22° centigrade is on an average 1.459. The melting- 
point of pure butter-fat, as now determined, varies between 
32° and 37° centigrade. (90° F. and 99° F.) 

* Gembloux, Belgium, Creamerj' Jo., London, No. 8, Vol. I. 



8 BUTTER-MAKING. 

When pure butter-fat is rapidly cooled, it solidifies into one 
solid mass; but if allowed to cool gradually, part of it solidifies, 
and part of it remains a liquid longer than other parts. This 
seems to indicate that some fats with a high melting-point 
separate out from the fats with a low melting-point. This 
behavior of pure butter-fat is not well understood, as it con- 
tradicts the now accepted theory that the different fats are 
in chemical combination with each other, rather than a me- 
chanical mixture of different glycerides of fat. 

Glycerides of Fat. — By this term we understand that the 
fatty acid radicals are in chemical combination with the glycerol 
(glycerine) radical, thus: 

Fatty acid radicals. 
Glycerol radical, f C4H7O2 (Butyric) 
C3H5 { C18H33O2 (Oleic) 
i C18H33O2 (Stearic) 

The chemical formula for glycerine is: 

Hydroxy! groups. 
Glycerol radical. Uti 

C3H5 I OH 

[ OH 

Comparing these two formulas, their difference and simi- 
larity are easily observed, and the reason why the term ''Gly- 
ceride of Fat " has been applied to such a compound is evident. 

Condition of Fat. — Whether the fats in milk exist in chem- 
ical combination, or whether they exist as glyceride of butyrin, 
stearin, olein, etc., in the form of a mechanical mixture, is a 
question in dispute. If they exist in the latter form, the com- 
position of the different fats must be thus: 

Butyrin. Olein. Stearin. 

[ C4H7O2 [ C18H33O2 [ C18H35O2 

G3H5 i C4H7O2 C3H5 j C18H33O2 C3H5 j C18H35O2 etc., 
[ C4H7O2 [ C18H33O2 [ C18H35O2 



COMPOSITION OF MILK. 9 

and the total fat made up of a mechanical mixture of these 
and the remainder of the fats in butter-fat. 

Richmond and other authors beheve that fat probably exists 
in milk chemically, as first mentioned and illustrated; because, 
if the fat were a mixture of glycerine tributyrate with other 
glycerides of fat, butyrin or glycerol tributyrate could be 
dissolved out by the use of alcohol. But this is not the case. 
Moreover, if butyrin existed separately in milk, it would be 
possible to distill it off under reduced pressure. This cannot be 
done. 

Theory in Regard to Films Enveloping Fat-globules. — The 
extreme minuteness of the fat-globules in milk renders it almost 
impossible to determine by direct microscopical observation 
whether there is a membrane around each globule or not. 
Fleischmann and Lloyd assert that, so far as they were able 
to detect, there is no real membrane surrounding each globule. 

The theory generally accepted in the past was that the 
only film surrounding the fat-globules was simply due to sur- 
face tension, or to the fact that the molecules of the fat have 
a greater attraction for themselves than they have for the 
molecules of the serum, in which they are held in suspension. 
In support of this two things are considered : 

(1) The natural milk-fat may be removed from milk and 
artificial fat substituted in its place. The resultant milk has 
characteristics similar to milk containing normal fat; that 
is, the emulsion which milk forms with the artificial fat is ap- 
parently like that formed with the natural fat. 

(2) If there were a special albuminous membrane around 
each fat-globule, cream should contain a higher percentage 
of albuminoids than milk. This, Richmond maintains, is not so. 

Dr. Storch concludes from extensive researches that there 
is a gelatinous membrane enveloping the fat-globules. His 
conclusions are based mainly upon the first three reasons 
given below. The other facts mentioned also support his> 
conclusions : 

(1) When milk has been stained with ammoniacal picro- 



10 BUTTER-MAKING 

carmine, and the cream washed with water until it is free 
from milk-sugar, a stained layer is present around each globule. 

(2) He has succeeded in isolating this gelatinous substance 
from cream and butter. Owing to its existence in these two 
substances, he assumes that it is also present in milk. 

(3) When ether is added to milk, the fat globules dissolve 
with difficulty, unless some alkali is added to the milk first. 

(4) Bichamp maintains that when ether is added to milk 
the fat-globules are enlarged due to the ether passing through 
the supposed membrane by the process of osmosis. He con- 
siders this fact sufficient to prove that there is a membrane 
encircling each globule. 

(5) Butter containing 85 to 86% fat is asserted by Rich- 
mond to have the same consistency as cream containing about 
72% fat at the same temperature. The solidity of butter 
is due to the close proximity of the fat-globules. Now, if 
cream with less fat has the same consistency as butter, the 
proximity of the fat-globules must be equal to that of the 
butter; this would indicate that there is a membrane and 
that this membrane increases the size of the fat-globules. 

(6) The fact that cream separated by centrifugal force is 
more easily churned than cream of same richness separated 
by gravity methods, would also be explained if the fat glob- 
ules in milk had such a membrane surrounding them. 

This membrane, or what is believed to be a membrane, 
Storch has isolated and analyzed. He finds it to consist of 
94% of water and 6% of proteid. 

The reasons deduced by Storch are strong; and the behavior 
of cream and butter renders it probable that there is such a 
membrane enveloping each globule of fat. 

Classes of Fats. 

There are two great classes or groups of fats present in the 
butter, namely: 

(1) Volatile and Soluble, 

(2) Non-volatile and Insoluble. 



COMPOSITION OF MILK. 11 

It was previously stated that little is known concerning 
the way in which the fatty acids are combined with glycerine 
in the milk; but, for the sake of convenience, the fats will be 
referred to as if they exist as separate glycerides of fat. 

The terms " Volatile " and " Non-volatile " are applied 
to the glycerides of fat, or to the fats as they exist in butter. 
Strictly speaking, this is not proper, as they do not assume 
the volatile characteristics until the glycerine separates from 
the fatty acids; it is only then that the latter becomes volatile. 

Volatile Fats. — The first group, or the volatile fats, include 
butyrin, caproin, caprylin, caprin, and laurin. Butyrin is the 
one present in the largest proportion. Laurin and caprin are 
partially non-volatile. Butyrin is the most important fat 
belonging to the volatile group. It is the most important 
quantitatively, and also qualitatively. So far as is known, 
butyrin is the least stable of any of the butter-fats. Under 
normal conditions, so long as the fatty acid remains in com- 
bination with the glycerol, it is not volatile nor soluble in 
water but as soon as separation takes place, due to the action 
of micro-organisms, or to the effect of light and air, then it 
becomes volatile, and escapes in the form of gas. According 
to the mass of evidence, these factors are the chief causes of 
rancidity in butter. 

It is also claimed that these volatile fats have the special 
properties of absorbing odors and gases to a greater extent 
than any of the other fats. This absorption takes place when 
fat comes into contact with the undesirable taints. For this 
reason it is essential that milk, cream, or butter be kept away 
from any foreign undesirable odors. These undesirable taints 
may also be imparted to the fat before the milk is drawn. 
If the cow is fed on undesirable food such as turnips, onions, 
garlic, etc., the milk from the cow assumes undesirable char- 
acteristic flavors, which can. easily be recognized in the finished 
product. On the other hand, such foods as well-cured sweet- 
clover hay, and bran, seem to impart desirable flavors to 
milk and butter. 



12 BUTTER-MAKING. 

The presence of these volatile fats in butter is quite uniform, 
and is a distinguishing feature of pure butter-fat. The detec- 
tion of adulteration of butter with foreign fats is based chiefly 
upon the presence of these volatile fats. The characteristic 
desirable flavor of butter is also beheved to be due to the pres- 
ence of the volatile fats. The volatile fats vary but shghtly 
during the different seasons of the year. They are present 
in the greatest proportion during the spring and early summer 
months, when cows are fed on grass, and also during the early 
stage of the period of lactation. They decrease gradually 
as the lactation period advances. 

About 8% of the total fats in milk is volatile fats. 

Non-volatile Fats. — This group constitutes about 92% of 
the total fats in butter. Chemists now agree that palmitin, 
stearin, olein, and myristin are the most important ones to 
be considered, as will be seen from the table quoted from Rich- 
mond. 

These non-volatile fats are of special importance, as the 
relative amount of each of these fats largely causes the varia- 
tion in the hardness and softness of the butter and butter-fat. 
The melting-point of these different fats varies according to 
the different investigators: olein is a hquid at ordinary tem- 
perature and melts at about 41° F. ; stearin, on the other hand, 
has a melting-point of about 150° F. ; palmitin also has a high 
melting-point, namely, about l42° F. ; myristin melts at about 
129° F. 

Olein has been found to be present in the greatest pro- 
portion during the spring, when cows are fed on grass. When 
cows are fed on normal dry food^ as in the winter time, it is 
present in a much less degree. This, together with the small 
increase of volatile fats, is the cause of the softer butter so 
frequent in the spring. The hardness of the butter in the 
fall or winter is due chiefly to the presence of a slightly increased 
amount of the fats, with a high melting-point, as mentioned 
above. 

From what has been said above, one is led to believe that, 



COMPOSITION OF MILK. 13 

by melting a sample of butter which contains these different 
fats, the fats with a low melting-point would melt first, and 
leave the remainder in an unmelted condition. Such is not 
the case. Butter-fat in this respect behaves a good deal hke 
different metals with different fusing-points. When they are 
melted and mixed together, cooled and then remelted again, 
they assume a common melting-point. It is the same way 
with butter-fat. It melts at a temperature of 91° to 
96° F. 

As the body temperature of cows (about 98° F.) is above 
this temperature, the fat globules are present in the milk in 
liquid form when milk is first drawn. A peculiarity about 
these fat-globules in milk is that the milk and fat may be cooled 
down below the melting-point of the fat of butter without 
the fat-globules in milk being solidified. It requires a tem- 
perature of between 60° and 78° F. before the fat-globules 
in milk begin to sohdify. When these small fat-globules are 
caused to unite, as during the churning process, they solidify 
at higher temperature. This behavior of the fat in milk evi- 
dently must be due to a relative change in the position of the 
molecules of fat during the process of cooling and warming. 
No definite explanations, so far as is known, have been given 
for this condition of the fat. 

The non-volatile fats found in butter-fat are practically 
the same as those found in other animal fats. 

Composition of Butter-fat. — In his " Dairy Chemistry, '^ 
Richmond gives the following composition of butter-fat, repre- 
senting the mean results obtained by different observers: 

^Butyrin 3.85% 

8% Volatile J Caproin 3 . 60% 

l Caprylin 55% 



Pat. 



, 92% Non-volatile. 



Caprin 1.9% 

Laurin 7.4% 

Myristin 20 . 2% 

Palmitin 25.7% 

Stearin 1.8% 

I Olein 35% 



14 



BUTTER-MAKING. 



Richmond also gives the percentage of glycerine and fatty 
acids in each of the different fats, as follows: 

Butyrin. . . 3.85% yielding 3.43% fatty acids and 1.17% glycerine 



Caproin. . 


. 3.60 


3.25 


" " .86 


Caprylin. . 


.55 


.51 


" " .10 


Caprin. . . 


. 1.9 


1.77 


" " .31 


Laurin. . . 


. 7.4 


6.94 


" " 1.07 


Myristin. . 


.20.2 


' 19.14 " 


" " 2.^3 


Palmitin . 


. 25.7 


' 24.48 


" ■' 2.91 


Stearin. . . 


. 1.8 


' 1.72 


" " .19 


Olein 


. 35 


' 33 . 60 


" " 3.39 



100 



94.84 



12.53 



Proteids (Albuminoids). 

The proteids of milk are present partly in solution and 
partly in suspension. They are present in a very complex 
chemical form. Some of the chemists reckon as many as 
eight different albuminoids or proteids in milk. Duclaux 
claims that there are only two kinds of albuminoids, the coagii- 
lable, and non-coagulahle casein. He has, by the use of a fine 
filter, been able to separate the fat and the coagulable from 
the rest of the serum. The amount of coagulable casein is 
claimed to vary considerably, and seems to depend upon the 
amount of lime phosphate present. The filtrate which Duclaux 
obtained from filtering the milk was clear and colorless, which, 
proves that the removal of the casein was quite complete. 
In order to remove casein from milk, a special filter (Chamber- 
land) is employed. Owing to this fact, we may consider the 
casein to be present in suspension or semi-solution. Noted 
chemists, such as Babcock, Van Slyke, Duclaux, Storch, Ham- 
marsten, Ritthausen, and Richmond, disagree upon the num- 
ber of albuminoid substances found in milk, and upon the 
chemical behavior of each. 

For all practical purposes it is safe to mention two, namely, 
(1) casein, and (2) albumen. Those two substances, as all 
agree, are present in milk, and constitute practically all the 



COMPOSITION OF MILK. 15 

albuminoids in milk. But after these two have been separated 
from milk a sHght precipitation can be obtained by treating 
the filtrate with alcohol. This has been called albumose and 
also lactoglobulin. From this resultant filtrate can again 
be separated a very small amount of material containing 
nitrogen. Dr. Babcock has obtained a substance from milk 
called fibrin. These latter substances, however, are present 
in minute portions, and are believed by some of the best scien- 
tists to be the same as the albumen, and their presence in the 
filtrate is due to incomplete precipitation of the albumen in 
the first place. 

Casein. — Casein is by far the most important of all of the 
albuminoids. It is the substance which forms the curd in 
cheese-making. In fresh milk, as is now understood, it is in 
chemical combination with lime salts. It is on this account 
that fresh milk shows the amphoteric reaction, which will be 
explained under the " Properties of Milk." The coagulation 
of casein by the addition of rennet or dilute acids is thought 
to be due to this union between the casein and hme. Fleisch- 
mann refers to this as the "caseous matter" of milk. The 
viscosity of normal milk is believed to be due in a large meas- 
ure to this condition of casein in milk. It causes the casein 
to be present in a colloidal condition. Wlien milk coagu- 
lates by natural or by artificial means, the union between 
the casein and lime phosphate is largely broken. 

Casein and albumen differ in composition, in that the casein 
contains phosphorus and less sulphur than does albumen. 
Fleischmann maintains that a substance called nuclein is 
associated with casein, and is not found in albumen. 

Casein is precipitated by the use of rennet and dilute acids, 
and coagulates spontaneously, due to the acid formed in the 
milk. The precipitates formed by the use of different pre- 
cipitating agents are not alike. The curd coagulated by ren- 
net contains more fat and calcium phosphate than the curd 
does which is precipitated by dilute acid or soured sponta- 
neously. If milk stands at air temperature for any length 



16 BUTTER-MAKING. 

of time after milking, the caseous matter (or the nitrogenous 
matter combined with Hme) tends to separate. The caseous 
matter of milk is not completely precipitated by heat, although 
heat partially destroys the union between the casein and lime. 
This destroys the action of rennet. Instead of getting a smooth 
sohd coagulum, a more flaky precipitate is obtained. For this 
reason milk for cheese-making should not be heated to a high 
temperature. By heating milk in a glass flask to a high tem- 
perature, and letting it stand for a time, it will be found that 
a mineral precipitate has settled to the bottom. This pre- 
cipitate is beheved to be a lime phosphate, which, previous 
to heating, was combined with the casein of the milk. By 
adding calcium chloride (CaCl) to milk which has been heated, 
its normal condition towards the action of rennet is again 
restored. 

Albumen. — If the casein is removed from the milk by 
precipitation, and then filtered off, the filtrate wih contain a 
substance which will precipitate when boiled. This is albumen, 
and is similar in character to albumen from the white of an 
egg. It differs from casein in that it is not precipitated by 
rennet or acids, but precipitates on heating. It does not 
contain any phosphates, but contains a comparatively large 
amount of sulphur. 

As the albumen is soluble in rennet and dilute acids, it 
can readily be seen that it is retained in the whey obtained in 
cheese-making. When albumen is present in small quanti- 
ties, as it is in normal milk, heating does not completely pre- 
cipitate it, unless the casein or curd is first removed. If, on 
the other hand, albumen is present in excess, as is the case 
in colostrum, the major portion of the albumen is precipitated 
when heat is applied, without first removing the casein. 

Sugar.- Milk-sugar occurs in milk to the extent of about 
5%. It varies very Httle in quantity, seldom falhng below 
3^% and seldom rising above 5^%. It occurs in solution, 
and is found in no other place in nature. 

Milk-sugar is the most unstable component of milk. It 



COMPOSITION OF MILK. 17 

quickly and easily decomposes. This decomposition is caused 
by micro-organisms. If these could be entirely excluded 
from the milk, it would keep for an almost indefinite length 
of time. As it is impossible under practicable conditions to 
entirely exclude organisms from the milk, the only way in 
which the growth of germs can be retarded and prevented, 
and thereby prevent the changing of the sugar into other 
products, is to cool the milk to a low temperature (50° F.), 
or to heat the milk to a sufficiently high temperature (180° F.) 
to destroy most of the germs. According to Van Slyke and 
Hart, the decomposition of the caseous matter produces free 
casein. When about .5% acid has developed in the milk, 
the free casein combines with the acid and forms casein 
lactate. 

The chemical composition of milk-sugar is Ci2H220ii +H2O. 
When a perfect decomposition of milk-sugar into lactic acid 
takes place, the following equation would represent the 
change : 

(Milk-sugar) (Lactic acid) 
C12H24O12 = 4C3H6O3. 

Such an ideal change, however, never takes place. In 
such a case, one gram of milk-sugar should produce one 
gram of lactic acid. In a number of experiments carried 
on by one of the authors of '' The Analysis of Cream During 
Different Ripening Stages," * the highest amount of acid 
produced from one gram of milk-sugar was .8. of a gram. 
This indicates that there are always accompanying by-products 
produced, besides lactic acid, when milk-sugar is being decom- 
posed in cream or milk. The sourness of milk is due to this 
change. The by-products which accompany the production 
of lactic acid are many and various. The most important 
ones are gases of different kinds, such as carbonic acid gas 
(CO2); marsh gas (CH4); hydrogen (H); and nitrogen (N). A 

* Thesis I. S. C, Ames, la. 



18 BUTTER-MAKING. 

small amount of alcohol, formic, acetic, and succinic acids are 
said to be normal accompanying by-products also. These 
by-products may also partially result from the breaking down 
of some of the other milk components. 

As milk-sugar is in perfect solution, it follows the water 
of milk, and in cheese-making nearly all of it passes into the 
whey. Commercially and chemically it is prepared from 
whey. It is a white, not very sweet powder, and is used for 
medicinal purposes to dilute pure, powerful drugs. It is also 
used extensively in the preparation of modified milk. 

Ash. — The ash of milk is present in very small quantities, 
and when viewed from such a standpoint it may first seem 
to be of small importance. On account of the effect of the 
mineral constituents upon the properties of milk, it is one 
of the most important components of the milk. It consists 
partly in solution, and partly in suspension. Babcock main- 
tains that about one-third of the usual ash constituents is in 
suspension, and that they consist chiefly of lime phosphate. 

All of the minerals in milk consist chiefly of potash, lime, 
soda, magnesia, and iron, combined with phosphoric, hydro- 
chloric, sulphuric, and carbonic acid. Calcium phosphate 
constitutes about one-half of all the ash constituents. They 
are named above, in order, according to the extent in which 
they occur in milk. 

Gases of Milk. — These do not normally exist in milk to 
such an extent as to enable chemists to determine them quan- 
titatively, but they are of great importance, owing to the 
effect they have upon the quality of the milk, viewing it in 
the commercial sense. 

Gases in milk may be divided into two classes according to 
their origin; namely, (1) those imparted to milk before milk- 
ing and (2) those which are formed and absorbed in milk 
later. 

(1) When freshly drawn milk has a characteristic cowy 
smell, which seems to be normal to all fresh milk. These 
gases are very volatile, and by cooling and aerating milk (differ- 



COMPOSITION OF MILK. 19 

ent processes of which are now in use in this country) these 
gases can, to a large extent, be eliminated. The amount and 
kind of taints existing in milk, immediately after it has been 
drawn, largely depend upon the food which the cow has been 
fed. Turnips, onions, and garhc, when fed to cows a short 
time before milking, cause undesirable gases or taints to exist 
in the milk. Good sweet hay, bran, and good grass are said 
to produce milk of superior quality, and containing no bad 
taints, except the cowy or animal taste, which is natural to 
all milk when first drawn. 

The milk yielded by cows pasturing in the Alps of Switzer- 
land is said by tourists to possess a pecuhar, not undesirable, 
spicy odor and flavor. It is maintained by the native people 
in Switzerland that the pecuhar flavor of the Emmanthaler 
cheese cannot be developed anywhere else in the world. This 
flavor they believe to be due to the kind of vegetation the 
cows feed upon in the Alpine pastures. In Denmark, the 
poor people who do not own much land, graze their cows along 
the roads where weeds of different kinds grow. Milk from 
such cows has a peculiar characteristic odor or taint. In this 
country it is a common occurrence to find that milk delivered 
by patrons who keep their cows on timber-land pastures has 
a peculiar weedy odor. Especially is this true in the fall or 
late summer. These flavors are somewhat difficult to remove 
by the ordinary process of aeration. By heating such milk 
to 160° or 180° F., and stirring occasionally, most of these 
taints pass off. An addition of a small amount of saltpeter 
also improves it. 

Too much emphasis cannot be placed upon the food that 
the cows receive. While it is true that much of the desirable 
aroma and flavor in butter are due to bacterial growth, the 
kind of food fed to cows is not without significance. It is 
a well known fact that districts such as Normandy and 
Denmark, which have become famous for their high quality 
of dairy products, have the best of pasture and winter 
feeds. 



20 BUTTER-MAKING. 

Besides the kind of food, some physiological disturbances 
of the cow may cause abnormal taints in milk. 

(2) Gases or taints which are formed in the milk or absorbed 
by the milk are due to fermentation and absorption respectively. 
The fermentation cause will be considered in a separate chapter, 
and the latter cause needs little explanation. It is a well known 
fact that milk, or any of its products, has the special property 
of absorbing odors which may be present in the surroundings 
of milk. For this reason, milk, as well as other dairy products^ 
should at all times be kept in clean utensils and pure surround- 
ings. 

Abnormal taints appearing in milk immediately after 
milking are due to absorption within the cow. Taints that 
develop on standing are due to bacterial growth in the milk, 
or to absorption from impure surroundings. In removing 
undesirable taints from milk the first step is to remove the 
inciting cause, and the second to cause as many of these taints 
as possil)le to escape by a process of aeration or pasteurization. 

Coloring-matter. — It is not known of what the coloring- 
matter in milk consists. A substance named lactochrome 
has been found in milk. So far as known, this coloring-sub- 
stance is closely associated with the fat called palmitin. The 
amount of coloring-matter varies during the different seasons 
of the year. It also varies according to the different breeds. 
During the spring of the year, when cows are first put on grass, 
the color of the butter-fat is always higher than it is during 
the latter portion of the summer. During the winter, the 
fat in milk is quite pale. By feeding the cows some succulent 
feed in the winter, such as silage, carrots, and beets, the color 
of the butter-fat becomes much higher. 

From this it would seem that the change in the color of 
the fat with the different seasons, and the food fed, is closely 
associated with chlorophyl, the coloring-matter of grass. 

Other Constituents of Milk. — It is said that constituents 
such as citric acid, urea, nuclein, lecithin, and galactase are 
present. Babcock maintains that he has discovered a sub- 



COMPOSITION OF MILK 21 

stance named fibrin. This seems to be similar to the nuclein 
mentioned by Fleischmann, if not the same. But as these 
substances are present to a very small extent, citric acid, urea, 
and fibrin being present to the extent of .12, .007, and .0002% 
respectively (Fleischmann and Babcock), they are of little 
importance. 



CHAPTER 11. 

MILK SECRETION. 

The Mammary Gland as a Secretory Organ. — The mam- 
mary gland of females belonging to the order of mammaha, 
secretes a fluid known as milk. This substance is strictly a 
secretory product. There are two kinds of glands present 
in the animal body; viz., the excretory and the secretory. Gen- 
erally speaking, an excretory gland is one which receives or 
absorbs the waste matter of the body, and causes it to be 
carried off without causing any marked change to take place 
in the substance excreted. A secretory gland is one in which 
the raw material is obtained from the blood and then manu- 
factured into a special different product within the gland 
itself. As an example of a secretory gland, the milk-gland 
of the cow's udder is an apt illustration. The glands in the 
mouth secreting saliva, and those in the walls of the stomach 
secreting the digestive fluids, are also secretory glands. 

Internal Structure of Cow's Udder. — The cow's udder is 
composed of two separate glands, the right and left halves. 
These two glands are • distinctly separated from each other 
by a fibrous tissue running longitudinally. This fibrous par- 
tition extends along the abdomen in front, and back to a point 
between the thighs of the cow. It also serves to hold the 
cow's udder in place. There is no connection at all between 
the right and left gland, and consequently milk cannot be 
drawn from the left side over to the right, and vice versa. 

Each of these right and left halves is again divided into 
two parts, thus making the cow's udder appear in quarters. 
The cow's udder may then be said to consist of two glands 

22 



MILK SECRETION. 



23 



on the right side, and two on the left side. The divisions 
between the two glands on the side are not entirely complete. 
That is, there is enough connection between the two glands 
on the same side to allow a portion of the milk to be drawn 
from the rear teat to the front teat on the same side, and from 



GLAND-LOBULE 
ALVEOLI 




Fig. 2. — Schematic figure showing cross-section of cow's udder; and also 
enlargement of epithelial cells in alveoli when cow is giving milk (1). Each 
alveolus is surrounded with a membrane called tunica propria. Cell 
nuclei not shown. When cow is in milk they are also enlarged. When 
not the epithelialjcells are flat and the nuclei small and spindle shaped (2). 

the front teat to the rear teat. The milk-glands proper are 
located near the abdomen and extend downwards into the 
udder a trifle. The remainder of the udder is filled with ducts, 
fibrous and connective tissue, muscle, nerves, and blood-vessels, 
the whole udder assuming a sort of spongy and open condition. 



24 BUTTER-MAKING. 

The teat is simply a cylindrical-shaped body, with a hollow 
tube extending down through the center of it. At the bot- 
tom of this opening, or at the end of the teat, there is a sphincter 
muscle. This muscle in some circumstances is drawn up very 
tight, while in other instances it is so loose that it will not guard 
the milk from escaping. In case the muscle is so tight that 
the milk can be drawn only with difficulty, it may be relaxed 
a trifle by entering a small, smooth wooden plug. This will 
usually dilate the opening sufficiently, so that the milk may 
be drawn with comparative ease. In some instances this 
muscle is so tight that it is necessary to relax it by the use 
of a sharp knife. This, however, should be done with sur- 
gical skill; otherwise the whole muscle is likely to be so injured 
as to cause the milk to leak away at all times. 

The upper part of this canal in the teat connects with 
what is called the milk-reservoir. The size of this reservoir 
varies in different cows. The average capacity of this milk- 
cistern is about one pint. The opening from this reservoir 
into the teat is also guarded with a muscle. Over this muscle 
the cow has little control. Over the muscle at the lower end 
of the teat the cow has no control whatever. " 

Opening into the sides and top of this reservoir is a large 
number of tubes, which are called milk-ducts. These milk- 
ducts extend from the reservoir up into the milk-gland. They 
radiate in all directions, divide and subdivide, so as to form 
a very large number of small tubes. These milk-ducts are 
surrounded with fibrous muscular tissue, nerves, and blood- 
vessels. They are all guarded by a special muscle at the 
junction to the main milk-ducts, from which they radiate. 
These muscles are so intimately connected with the nerves 
and muscular system of the cow that she is able to open and 
close them at will. There are very few cows that are not 
able to hold up their milk during nervous and exciting periods. 
It is a common occurrence for a milker to get only a small 
part of the milk from a cow. This small amount is the portion 
which is present in the teat and milk -reservoir. Some cows 



MILK SECRETION. 25 

are able to hold up this milk also, but the majority of cows 
cannot perfectly control the muscle which guards the en- 
trance to the teat. The milk which is present in the milk- 
ducts and which has to pass through these junctions referred 
to above, can be held up by most cows at will. 

All of these small milk-ducts end in small sack-like bodies. 
Each of these dilated portions is called the gland-lobule 
or ultimate folHcle. These gland-lobules enclose numerous 
individual microscopical bodies called alveoli or acini. These 
alveoli constitute the organs which possess the proper secre- 
tory functions. These alveoli are lined on the outside with a 
membrane called the tunica propria. Next to this membrane 
is a layer of cell-tissue. The inside layer is composed of cells, 
which are named the epithelial ceUs. These epithelial cells 
within the alveoli are supplied with blood from the cow's 
system. During lactation they assume a different form. 
When the cow is yielding milk abundantly, these cells swell 
and extend into the cavity of the alveoH. When the cow is 
not in milk these alveolian cells become flat. A certain number 
of alveoli is tributary to one particular duct leading from the 
gland-lobule into still larger milk-ducts. 

Each aggregation of gland-lobules, tributary to one milk- 
cistern, constitutes a lobe, and may be likened to a side branch 
of a bunch of grapes. Each separate grape may represent 
a gland-lobule. The seeds within the grape, if we imagine each 
seed to be hollowed out and lined with small column-like 
bodies, may be likened to the alveoli. These column-like 
bodies would then represent the epithelial cells. The stem 
leading from each individual grape may represent the small 
duct which carries the milk on to the larger ducts. The main 
stems of the bunch may represent the larger ducts that enter 
into the milk-reservoir. The air which everywhere fills the 
openings or interstices of the various parts of the bunch of 
grapes may be likened to the fibrous fatty tissue between the 
alveoli and the lobules of the gland. 

Theories of Milk Secretion. — Although the theories of milk 



26 BUTTER-MAKING. 

secretion have been studied considerably, many things in this 
connection are not well understood. Previous to the year 
1840 it was thought that the only function of the milk-gland 
was to filter the milk as it transuded from the blood. It was 
supposed that the ciuality and quantity of milk depended 
entirely upon the food. The theory has also been advanced 
that the major portion of the milk constituents was a decom- 
position of the product of the lymph bodies of the blood. It 
was believed that the lymph bodies were a source of nourish- 
ment to the foetus, and that the calf received its nourishment 
from the same source after it was born as it did previous to 
birth. It was supposed that after the birth of the calf the 
opening on the uterus through which the food was supphed 
was closed, and that a new opening was formed in the milk- 
gland. These two theories have now been practically over- 
thrown. It has been demonstrated that the major portion of 
the milk is formed within the milk-gland. The fat, casein, 
milk-sugar, and part of the albumen are supposed to be formed 
in the udder. This conclusion is substantiated by the fact 
that these substances do not appear in the blood, at least not 
to such an extent as to warrant the assumption that they are 
not manufactured in the cow's udder. The total amount of 
fat in the blood of the cow would not equal the fat in the milk 
from one milking. 

By some it is maintained that the substances in milk which 
are found in solution may be transuded directly from the 
blood. Here again milk-sugar is found to be in perfect solu- 
tion in the milk, but this substance can be found nowhere in 
nature besides in milk. It is not present in the blood of the 
animal, consequently it must be manufactured within the 
gland itself. The water of milk, and the ash constituents which 
are in solution, are probably transuded directly fiom the blood. 
No attempts have been made to determine definitely how 
casein and albumen are formed within the gland. 

The theory advanced for the formation of fat is, that the 
epithelial cells break down and form fat. When the breaking- 



MILK SECRETION 



27 



down process is completed, the transformed cells appear at 
the opening of the alveoli in the form of distinct fat-globules. 
This is supposed to be the origin and formation of fat-globules 
in milk; so it may be said that so far as known the fat 
is the result of a breaking down of degenerated epithelial cells. 
Dr. Bitting asserts that the formation of milk solids in the 
cow's udder is probably due to a metaboUc process rather than 




Fig. 3. — A schematic figure showing the course of the artery leading to the 
mammary gland and the veins returning to tlie heart. The light-colored 
Unes represent arteries and the dark-colored lines the veins. (From 
Bitting, Twelfth An. Report, Indiana.) 

to a degenerative. Colher found that a cow giving a normal 
amount of milk would secrete about 136,000,000 fat-globules 
per second. He also suggests that a cow secretes about 5 
pounds of milk solids per day. As a cow's udder weighs only 
about 2^ pounds, the whole udder would have to be renewed 
twice daily. This is not consistent with our present knowledge 
of tissue building. 



28 BUTTER-MAKING. 

The chief incentive to milk secretion is maternity. As soon 
as the young mammaUa is born the blood which went to the 
uterus to supply the calf is turned towards the udder instead. 
As soon as this current of blood begins to flow, all of the blood- 
vessels and capillaries in the cowl's udder swell. This causes 
the minute blood-vessels or capillaries which form a network 
in the walls of the alveoli to swell. This swelling stimulates 
the epithelial cells to activity. 

Conditions Affecting Secretion of Milk. — There are a 
great many conditions which affect the milking capacity of a 
cow. These conditions may be conveniently grouped into two 
classes according to their causes: (1) conditions which are con- 
trolled largely by man, and (2) conditions which are inherent 
to the cow. 

1. Some of the chief conditions which reduce the secretion 
of milk and are largely controlled by man are: improper care 
and treatment of the cow, lack of proper food, incomplete and 
improper milking, irregularity, and long periods between 
milkings. Pregnancy, nervousness, or excitement of any kind 
affect the proper working of the milk-glands considerably. 
These latter causes, however, are not always controlled by man. 

2. Without denying the influence of those conditions men- 
tioned above, the conditions which chiefly affect the milk- 
secreting capacity are inherent. It does not matter how much 
good care and food a cow receives, if she does not possess 
these inherent necessary qualities. As was mentioned before, 
the milk-secreting capacity depends upon the number of gland- 
lobules, upon the amount of blood ivhich is supplied to these secre- 
tory parts, and upon the capacity of the cow to digest and assimilate 
food. 

The number of gland-lobules is believed to increase until 
the cow is about seven years old. The milk-secreting glands 
are present only in a rudimentary form, until the cow has had 
her first calf, or is well advanced in the first stage of pregnancy. 
The gland-lobules then increase in number up to the age of 
about seven. The relative number of lobules in the cow's 



MILK SECRETION. 29 

"udder can only be approximately ascertained. The size of 
the udder in some measure indicates this. A cow with a large 
flexible udder is usually a good milker, due to the fact that a 
large udder usually contains a large number of gland-lobules. 

The amount of blood which is turned through the cow's 
udder to supply the milk-secreting cells may approximately 
be ascertained by the size of the blood vessels. The blood 
enters the udder from the heart near the region of the hips. 
It then passes down through the udder, along the abdomen 
just beneath the skin, until it reaches about midway between 
the flank and the girth. At this place it penetrates the abdom- 
inal wall and enters the thorax. The place at which the blood 
penetrates the abdominal wall may be felt with the finger. 
It is supposed that the size of this hole is in some measure 
indicative of the milk-producing capacity of the cow. This 
opening in the abdominal wall is called the milk-hole or milk- 
fountain. Large irregular veins are considered a much better 
indication of good milking properties than small straight veins. 

The formation of gland-lobules is entirely inherent in the 
cow. The only way that these may be increased is through 
selection and breeding. The amount of l)lood which passes 
through the cow's udder is also largely inherent, although 
this may in a small measure be affected by the amount and 
quality of food given to the cow. It should at all times be 
remembered that a cow is not a mere receptacle into which 
so much food can be introduced, and so much milk drawn 
from the other end. After giving due credit for the influence 
of all other conditions, we must still recognize that the inherent 
conditions affecting the secretion of milk are the most important. 

External Appearance of the Udder. — A cow's udder should 
be well and symmetrically formed. It should be square, wide, 
extend well along the abdomen of the cow, and back up between 
the thighs. When the udder is empty it should be soft and 
flexible. The teats should be medium large, should be placed 
well apart, and should point downwards. 

There should be Httle or no depression in the udder between 



30 BUTTER-MAKING. 

the teats; that is, each quarter should not appear distinct 
and separate when viewed from the exterior. 

The cow's udder should be covered with fine soft, downy 
hair. A light golden yellow is said to be indicative of a good 
quahty of milk. 

A firm, fleshy udder is undesirable. In the first place, it is 
not indicative of good milking qualities, and, secondly, such 
an udder is predisposed to inflammatory diseases. 

Milk-fever. — This is a common disease in fresh cows. 
It is due to a congested condition of the cow's udder. The 
decomposition products of the colostrum milk in the udder 
are absorbed by the blood, and produce the characteristic 
symptoms of milk-fever. Dr. Peters, of the Nebraska Experi- 
ment Station, says that a good and simple remedy for a diseased 
udder is to pump it full of air. This can be accomplished 
with an ordinary bicycle pump. After some air has been 
pumped in, then the cow's udder should be worked or massaged 
with the hand so as to cause the air to pass through the quarter. 
He claims that the udder can thus be restored to its normal 
condition very quickly, thereby preventing and even curing 
milk-fever. In case the udder is caked very badly, apply a 
hot poultice. Small five- or ten-pound bags filled with bran 
and kept hot is a good substance to use. A compress 
is also used. This consists simply of using a piece of heavy 
cloth. Put it on so that it lifts up the entire udder, and tie 
it over the back of the cow. Straw should be put underneath 
it on the back so that the cord does not injure the animal. 



CHAPTER III. 
PROPERTIES OF MILK. 

Color. — The color of normal milk ranges between bluish 
white and golden yellow, according to breeds, foods, and sea- 
sons of the year. The milk yielded by Jersey cows generally 
is more yehow, due chiefly to the larger amount of fat which 
it contains. Holstein cows yield milk of a whiter color. Foods 
such as grass and certain roots (mangles and carrots) have 
the power of giving to milk a higher color. As has been pre- 
viously mentioned, the coloring substance in milk has been 
named lactochrome, and so far as known is associated with 
the palmitin fat. 

Flavor. — Milk has a sweet flavor, and a faint odor. Fresh 
milk has a pecuhar cowy taste and odor, which pass off when 
exposed to the air. The flavor is affected by foods and con- 
ditions of the cow, as mentioned under '' Abnormal Milk." 

Opacity of Milk. — Milk is opaque, except when seen in 
very thin layers; then it is shghtly transparent. The opacity 
of milk is due to the presence of the fat and nitrogenous mat- 
ter. When these substances are filtered away on a fine clay 
filter (the Chamberland), the filtrate which passes through 
is clear and transparent. It has been maintained that the 
fat in milk is the chief cause of its opacity, and that the per- 
centage of fat could be determined according to the degree 
of opacity and transparency of milk with an instrument named 
pioscope; but it was soon found out that the size of the 
fat-globules, as well as the number, had considerable influence 
upon the degree of opacity of milk. For that reason, this 
method of determining the amount of fat in milk was not 

31 



32 BUTTER-MAKING. 

reliable. The fat-globules themselves are said to be almost 
transparent, yet the color and opacity of milk is largely due 
to their presence. This characteristic may perhaps be explained 
by assuming that the fat-globules in milk deflect the light 
instead of allowing it to pass through them. 

The opacity of milk, after the fat has been removed, is 
due to the presence of nitrogeneous matter. After the fat 
has been removed from the milk, the milk still continues to 
be opaque. When the albuminoid matter has been removed 
and filtered off the filtrate becomes clear and transparent. 

Chemical Reaction of Milk. — Milk when fresh shows an 
amphoteric reaction, which means that it exhibits both an 
alkahne and an acid reaction when tested with Htmus paper. 
It turns blue htmus paper red, and red litmus paper blue. This 
peculiar behavior of milk is said to be due to the caseous matter 
in the milk, which itself has an acid reaction, but the remainder 
of the serum has a slight alkaline reaction. By testing the 
reaction of fresh milk with a tenth normal alkali solution, 
and using phenolphthalein as an indicator, it will be found 
to give an acid reaction. After standing, milk soon becomes dis- 
tinctly acid, which is due to a change of the milk-sugar into 
acids, chiefly lactic acid, through the action of micro-organisms. 
Richmond maintains that the amphoteric reaction of milk 
has acquired a false importance, as he believes that the neu- 
trality, as measured by the action of litmus paper, is not chemi- 
cal neutrality. 

Specific Gravity of Milk. — By specific gravity of milk we 
mean the weight of the milk as compared to that of an equal 
volume of water at the same temperature. If a certain volume 
of water weighs 1000 pounds, an equal volume of milk at the 
same temperature and under the same conditions, will weigh 
about 1032 pounds. Reducing the figure to a basis of 1, as is 
always done, the comparison between the two equal volumes 
of water and milk will be 1 and 1.032. This latter figure 
represents the average specific gravity of normal milk. 

It can be readily seen that the correct specific gravity can 



PROPERTIES OF MILK. 33 

only be obtained at one given temperature, for, as the tempera- 
ture of the substance becomes higher, the density of it grows less, 
and consequently the specific gravity will be less. The tempera- 
ture at which the lactometers are standardized is 60° F. 

The variations in the specific gravity of milk will also vary 
according to the relative variation in amounts of the different 
components of milk. If a sample of milk is rich in sohds not 
fat, as, for instance, skimmed milk, the specific gravity will be 
high and usually between 1.033 and 1.037. If the sample of 
milk is rich in fat, as, for instance, in cream, the specific gravity 
will be less. 

By adding water to milk, the specific gravity of it is lessened. 
Owing to this fact it was first thought that adulteration of milk 
with water could be detected by testing its specific gravity. 
But this method was soon found to be erroneous, as it is 
possible to take cream away and add water in such a proportion 
as not to alter the specific gravity of the sample. A low specific 
gravity of nnlk may, however, cause the suspicion that the milk 
has been adulterated, and the test for water adulteration can 
be supplemented by testing it for fat. 

As has been mentioned before, the lactometer reading should 
be taken at 60° F. If the temperature of milk is above or 
below, corrections must be made. The amount of correction 
which will give approximate results is .1 of a degree added to 
the lactometer reading for every degree Fahrenheit of tempera- 
ture the milk is above 60° F., and also .1 of a degree subtracted 
from the lactometer reading for every degree of temperature the 
milk is below 60° F. The temperature of milk when tested for 
lactometer reading should never go any lower than 10° below 
60°, nor any higher than 10° above 60°. Tliis would leave the 
range of temperature between 50° and 70° F. 

In chemical laboratories, the specific gravity of milk is 
usually determined by the use of a picnometer. 

In practice there are three instruments in general use for 
determination of lactometer reading, or specific gravity, viz.: 
Quevenne lactometer, New York Board of Health lactometer 



34 



BUTTER-MAKING. 



and the ordinary hydrometer. The Quevenne lactometer is the 
one that is used chiefly in creameries. The graduation of each 
one of them is given in the accompanying diagram. It may be 

n n 



s N a 

" S " Specific Gravity Scale., 
" N " New York State. 
" Q" Quevenne, 
Fig. 4. — Comparative graduation of lactometer stems. 

seen from the figures that in order to change the Quevenne 
lactometer reading into specific gravity, all that is necessary is 
to add 1000 and divide the sum by 1000. In order to change the 



PROPERTIES OF MILK. 35 

specific gravity into lactometer reading the reverse process will 
give correct results. 

The hydrometer gives the specific gravity directly. The 
Board of Health lactometer has a special graduation. In 
devising this lactometer it was thought that 1.029 was the 
minimum specific gravity of unadulterated milk. The scale on 
this lactometer was made from zero to 120; zero marking the 
point which represents the specific gravity of water, namely, 1. 
100 is the point which is assumed to represent the least specific 
gravity of milk 1.029. If the specific gravity of a certain 
sample of milk fell to 90, it indicated that there was 10% of 
water present. If it fell to 80, it indicated that there was 20% 
of water, etc. 

In order to calculate the total solids, and solids not fat, of 
milk, it is necessary to know the lactometer reading, and the 
percentage of fat content. Knowing these factors, by the use 
of the following formula given by Farrington and Woll, and 
deduced from Fleischmann's work, the total solids, and sohds 
not fat, can be found: 

SoUds not fat= ^ lact. reading + .2 times the fat. 
Total solids = fat + sohds not fat. 

Natural Separation of Milk and Cream. — When milk is 
allowed to stand quietly for a short time, a layer having a rich- 
yellow color comes to the surface. This is the cream, and 
contains most of the fat. This separation is due chiefly to the 
difference in weight, or specific gravity, of the fat-globules and 
the serum. The force which acts upon the globule of fat is the 
difference in weight between the fat-globule and the serum 
which it displaces, minus the resistance force with which it 
meets in its upward passage. In milk with a high degree of 
viscosity this force is great. In milk of a limp and liquid 
consistency this force is smaller. By adding water the vis- 
cosity of milk is reduced considerably, and the specific gravity 
of the serum is also decreased. But the effect of the added 
water upon the viscosity is greater than the effect the water has 



36 



BUTTER-MAKING. 



upon the specific gravity of the serum; hence, by adding water 
to milk, the resistant force is decreased to such an extent as to 
get a more rapid and more efficient separation of the fat. The 
water dilution separators are based upon this principle. In 
normal milk, the amount of fat left in the skimmed milk by 
natural creaming is about .4%. The fat which is left in this 
skimmed milk is largely composed of very small globules. 
This is due to the fact that the resistant force of these small 
globules is equal to or greater than the buoyant force acting 
upon them. 




Fig. 5. — Standardized milk. Showing the amount of cream on milk con- 
taining the designated per cent of butter-fat. (From Bui. 92, 111.) 

This completeness of natural skimming is to a certain extent 
based upon the mathematical law which is stated as follows: 
' ' The surfaces of two spheres are to each other as the squares of 
their diameters, and their cubical contents are to each other 
as the cubes of their diameters." The larger the globules are, 
the greater the surface is, and the greater the resisting force to 
which they are subjected. From the law stated it can be seen 
that as the size of the globule increases, the cubical content 
increases more rapidly than the surface. If a fat-globule were 
split up into smaller ones, there would be more surface exposed 



PROPERTIES OF MILK. 37 

to the serum than was the case while the fat was present in 
one globule. 

For illustration, take two globules of fat having a diameter of 
4 and 2 inches respectively. The squares would be 16 inches 
and 4 inches respectively; their cubes would be 64 inches and 
8 inches respectively. It will thus be seen, according to the 
law quoted above, that the larger globule has a surface only four 
times as great as that of the smaller one ; but the cubical content 
of the larger globule is eight times that of the smaller one. This 
illustrates why the large globules rise in cream quicker than 
the small ones. In this particular instance the upward force 
the larger globule is subjected to is eight times greater than 
that of the smaller one, while the resistance force is only four 
times as great as that of the small one. 

Adhesion of Milk. — Normal sweet milk adheres to wood, 
glass, and metals to a greater extent than does water. Whole 
milk has greater adhesive properties than skimmed milk. 
A paper moistened with milk or cream makes a label that 
will stick to any dry object; the same paper moistened with 
skimmed milk has less adhesive power. The adhesive prop- 
erties of milk are also due to the condition of the nitrogenous 
matter. This fact is made use of in painting and whitewashing. 
Slacked lime, when mixed with buttermilk, or milk of any 
kind, gives a wliitewash which will remain on objects much 
longer' than that made by mixing with water. 

Viscosity of Milk. — Milk is more viscous than water. The 
degree of viscosity of fresh milk varies chiefly with the tem- 
perature and fat content. So far as understood, the lower 
the temperature, the greater the viscosity. Development of 
acid, and high temperature lessens the viscosity of milk. Pas- 
teurized milk or cream is less viscous than the same milk or 
cream unpasteurized. This lack of body can again be restored 
by adding a little viscogen, as recommended by Babcock 
and Russell. It is advisable not to use it, however, as it does 
not add materially to the nutritive value of milk. It merely 
restores the body. 



38 BUTTER-MAKING. 

The great viscosity of thick and cold cream has been 
encountered by most butter-makers when attempts have 
been made to churn cream under such conditions. It adheres 
to the inside of the churn and does not agitate. It simply 
rotates with the churn. Cream that is cold and thick 
whips more easily than thin and warm cream. The viscosity 
is so great that the air incorporated cannot escape so easily. 
In ice-cream making, a greater yield is obtained by using 
cold and thick cream. The air, when once incorporated, 
cannot easily escape, owing to the great viscosity of such 
cream. 

Specific Heat of Milk. — The specific heat of milk is less 
than that of water; that is, it requires less heat to warm a 
definite amount of milk to a certain temperature than it does 
to heat the same quantity of water to the same temperature. 
It also takes less ice to cool the same volume of milk to a cer- 
tain temperature than it does to cool the same quantity of 
water to the same temperature. The specific heat of milk 
is, according to Fjord, .94. The specific heat of cream is 
about .7. It varies according to the percentage of fat in the 
cream. The specific heat of butter is about .4. From these 
figures it will be seen that it takes less heat to warm milk, 
cream, and butter, and less cold to cool the same substances, 
than it does to heat and cool water; but it takes a longer time 
to heat or to cool milk, cream, and butter; that is, the milk, 
cream, and butter are not as rapid conductors of heat and 
cold as is water. 

The maximum density of milk is not, like water, at 4° C. 
but at about .3° C. The boiling-point of milk is a trifle higher 
and the freezing-point a trifle lower than that of water. 

Effect of High Heating (i8o° and above) on Properties of 
Milk. — The chief effects of heat upon milk may be summarized 
in the following headings : 

(1) It destroys nearly all germs present in the milk. 

(2) It diminishes the viscosity, or body. 

(3) It drives off gases 



PROPERTIES OF MILK 39 

(4) It imparts a cooked taste (especially if not heated and 
cooled properly). 

(5) It precipitates some of the albuminoids and ash con- 
stituents. 

(6) It destroys the properties of enzymes present in milk. 

(7) It divides or sphts up the fat globules. 

(8) It carameHzes some of the sugar. 

1. Destroys Nearly All Germs. — Heating milk to a tem- 
perature of about 180° F. for ten minutes destroys most of 
the germs present in milk. This is the temperature used 
chiefly in creameries for pasteurization. The details concern- 
ing the different effects of temperature upon growth of germs 
properly comes under the heading of bacteriology, and will 
be referred to more in detail in the chapter on '' Bacteria in 
Milk." 

2. Diminishes the Viscosity, or Body. — Heating milk or 
cream diminishes the viscosity of these substances; that is, 
the body or consistency is lessened; and in cities where milk 
or cream is sold directly to consumers, heated milk appears 
as if it had been adulterated. This diminution in the body 
is claimed to be due to a breaking up of the fat-globules and 
the caseous matter. The chemical union of some of the cal- 
cium salts and the casein is altered or destroyed. 

The consistency of milk or cream can be restored by adding 
a substance named viscogen. Russell and Babcock* advise 
this method of overcoming the apparent defect caused by 
heating. It consists of making a strong solution of cane-sugar 
and mixing it ^\dth freshly slacked hme. This mixture is 
allowed to stand, and the clear solution coming to the top 
is the viscogen, which, when drawn off and used in the pro- 
portion of one part of viscogen to from 100 to 150 parts of 
cream, restores the body of cream or milk. This is due to 
the fact that viscogen causes the fat-globules to cluster together 
again, and the lime in the viscogen may combine with the 

* Bulletin Xo. 54, VMsconsin. 



40 BUTTER-MAKING. 

nitrogenous constituents in such a way as to aid in the resto- 
ration of the bod}^ of the cream or milk. 

Nearly all dairy laws forbid the addition of any foreign 
substa.nces to milk or cream. If viscogen is added, Babcock 
and Russell suggest to name it visco-milk, visco-cream, etc. 
When this modification is made, then no objection can be 
raised to its legitimate use. 




Fig. 6. — Microscopic appearance of milk, showing natural grouping of the 
fat-globules. Single group in circle, highly magnified. (From Bui. 64, 

Wis3 

3. Drives off Gases. — Wlien milk is heated, taints, and 
gases of different kinds pass off to some extent. This is facili- 
tated by heating and stirring in an open vessel. Many of 
these gases also escape when milk is aerated and cooled in a 
pure atmosphere. 

4. Imparts a Cooked Taste. — When milk is heated to 160° F. 
or above, it assumes a distinctly cooked taste, which makes it 
disagreeable as a food for many people. On this account, 
milk for city supply in America is generally not heated. 
In a few cities where milk is consumed directly, heating and 
coohng (pasteurization) has been generally introduced. It 
is said that people can become accustomed to this cooked 
flavor and acquire a hking for it. When milk is not heated 
higher than 180° F., nor exposed to the heat very long, and 



PROPERTIES OF MILK. 41 

cooled quickly, the cooked taste can be greatly reduced and 
almost entirely avoided. Where heating or pasteurization 
of cream has been adopted, as in some creameries, the pre- 
vention of tliis cooked flavor in the butter is of vital importance. 
The reason why this cooked flavor forms in milk when 
heated is not well understood. It is supposed to be due to 
the effect wliich heat has upon the nitrogeneous constituents 
of milk. 

5. Precipitates Albuminoid and Ash Constituents. — T^Tien 
milk is heated, there is a tendency for the soluble salts and a 
portion of the albuminoids to be thrown do-^m, or changed into 
an insoluble form. 

The higher the milk is heated, the greater is this tendency. 
By subjecting a sample of milk in a flask to intense heat, and then 
allowmg it to stand, a fine white sediment will be deposited on 
the bottom. This is believed to be minerals precipitated from 
the milk. 

AMien milk has been heated to about 170° F., and cooled, 
rennet is imable to precipitate the curd in a normal way. The 
curd resulting from adding rennet to pasteurized milk is floccu- 
lent in nature. It does not assume that smooth and even 
texture that curd from raw milk has when precipitated with 
rennet. This abnormal behavior of pasteurized milk towards 
rennet can be reestablished by adding a small quantity of 
calcium chloride (CaClj. Whether this would effect the 
quality of cheese materially has not yet been determined 
definitely. According to G. Fascetti,* if pasteurized milk is 
used for cheese-making, the cheese ripens more slowly than 
when made from raw milk. The same investigator also claims 
that a larger quantity of cheese is obtained per 100 parts of milk 
when pasteurized milk is used. 

6. Destroys Properties of Enzymes. — As was mentioned in 
the composition of milk there is a substance normal to milk 
named galactase. This is an enz}Tne. By heating milk to 

* Exper. Sta. Record, Vol. 1.5, No. 10, 1904. 



42 BUTTER-MAKING. 

about 175° F. the properties of the enzyme are destroyed Owing 
to this it is easy to detect whether a certain sample of milk has 
been pasteurized or not. Galactase is present in so small a 
quantity that it could not be determined in milk quantitatively. 
It must be detected in a qualitative way. 

The test used and invented by Storch, of Copenhagen, 
Denmark, is to put a small quantity of milk in a test-tube, add to 
it a small quantity of a weak solution (2%) of hydrogen peroxide 
(H2O2), a small quantity of potassium iodide, and a little starch 
solution. The whole mixture is then shaken. If the mixture does 
not change in color, it has been heated to at least 170° F. If it 
turns blue, it has not been heated to a sufficiently high tempera- 
ture to destroy the properties of the enzyme present in the milk. 
Another test which can be used in distinguishing raw milk from 
scalded or boiled milk is to take 10 cubic centimeters of the milk 
to be tested, atld 1% of recently prepared aqueous solution of 
"Ortol," and then one or two drops of hydrogen peroxide. If 
the milk has not been heated, a vivid red color is produced. 
Heated milk shows no effect. 

7. Divides the Fat-globules. — The fat-globules in normal 
milk are grouped in minute clusters. When milk is heated, 
these clusters break up, and each globule exists more or 
less independently. When heated to an excessively high 
temperature, and exposed to this temperature very long, the 
fat-globules tend to run together. This can be proved by 
heating milk in an open vat for about half an hour. A small 
amount of yellow fat will then be seen floating on the top. 

8. Caramelizes the Sugar. — The brownish color which the 
milk assumes when it is heated excessively is due to a change 
which the milk-sugar undergoes. Fleischmann claims that the 
sugar begins to change into a substance known as lacto-caramel 
at a temperature of 160° F. This change, however, is not 
pronounced enough to be apparent in the color, unless the milk 
is heated a long time. The higher the temperature is, and the 
longer it is exposed to the heat, the more pronounced is the 
change. 



PROPERTIES OF MILK. 43 

General Remarks. — While all of the above changes have 
been found by investigators to take place when milk is heated, 
they can, in a measure, be avoided, if special precautions are 
taken in the heating and cooling of milk with the special, 
recently improved forms of apparatus for heating and cooling 
milk. The heating to 160° F. can be accomplished without 
changing materially the chemical or physical properties of 
milk.* Rapid heating and rapid cooling seem to be two essen- 
tials in order to prevent changes from occurring in the milk. 

* Fjadon, Koshe, and Hertel in Exp. St. Record, Vol. 14, No. 5. 



CHAPTER IV. 

FERMENTS IN MILK. 

Definition. — Tho (*li:ui<i;os which milk undergoes by standing 
at a suitable teni])eratui'o are called fermentations. The 
causal agents are called ferments. There are two kinds of 
f(M-ments in milk; viz.: (1) the organized, and (2) the unorgan- 
ize(L The latter includes the enzymes. So far as known, only 
one pre-existing enzyme is found in milk. This one was dis- 
covered by Russell and liabcock. They named it galadase. 
It is a tryptic ferment. This galactase is present to such a 
small (>xtent in milk (lint it exercises very httle influence upon 
the characteristics of milk. If the milk were rendered entirely 
st(>ril(^ or fi'ce from organized ferments, the fermentative changes 
would proceed at an unusually slow rate. The galactase has 
been suggested to be of some im])ortance to the butter-making 
industry. The propei-ties of galactase, like those of any other 
enzyme, are destroyed by heating to or above a temperature of 
about 175° F. 

The organized ferments are by far the most important to the 
dairy industry. It should be understood in this connection 
that the organized ferments may produce unorganized ferments, 
or enzymes, as products, but these produced enzymes do not 
exist in milk, like galactase, when it is first drawn from the cow. 
The oi-ganized ferments of milk consist chiefly of bacteria. 
There are present also some yeasts and molds. 

It is a common impression that Inicteria are animals, which 
is incorrect. Bacteria are minute niicrosco})ical plants, belong- 
ing to the lowest order of plants in the vegetable kingdom. 
Bacteria differ from the ordinary plants that we see, in that 
they are composed of a single cell containing protoplasm, 

44 



FERMENTS IN MILK. 45 

while the plants that we see in every-day life are aggregations 
of cells. Some bacteria are motile, while others are not. 

Size and Shape of Bacteria. — In size, bacteria are the smallest 
organisms that exist, so far as known. The size varies con- 
siderably. Russell * gives the average diameter as 37701777 
of an inch. They are so inconceivably small and light that 
nine hundred billions of them would only weigh ^V ^-'^ ^'^ 
ounce, t 

Bacteria also vary considerably in shape. They are as a 
rule classed into three groups: (1) The bacillus or rod-shaped; 
(2) The coccus or ball-shaped; (.3) The spirillum or spiral- 
shaped (like a corkscrew). Some types of bacteria are clas- 
sified according to the way in which they adhere to each other. 
For instance, when tw^o cocci occur together and form a pair-, 
they are called diplococci, when bacteria occur in chains, 
they are called streptococci, when bacteria appear in bunches 
they are called staphylococci, etc. 

Favorable Conditions for Bacterial Growth. 

Food. — Bacteria are like other plants in nature, — they need 
food for their existence. However, they require their food in 
solution. Nitrogen, carbon, oxygen, and mineral matter are 
essentials for bacteria. These substances are furnished in 
abundance in milk from casein, albumen, milk-sugar, and the 
mineral salts. Butter-fat in milk is said to be of little value 
as a food for bacteria. 

Some bacteria prefer a substance having an acid reaction in 
which to grow; others thrive best in an alkahne medium. 
Most bacteria, however, prefer a neutral or slightly alkahne 
substance. Darkness is essential to some bacteria, and is 
preferred by the majority of the different species. Bright 
sunlight is a very effective germicide. It is fatal to all species, 
so far as known. Some germs require air for their growth. 
These are called aerobic. Others again grow only in the 

* Dairy Bacteriology. t Milk, Its Xature and Composition, by Aikman. 



46 



BUTTER-MAKING. 



absence of air. These are called anaerobic. Some grow under 
either or both conditions, and are called facultative aerobic or 
facultative anaerobic. 

Temperature. — Favorable temperature is essential to bac- 
terial growth. Temperature is, indeed, the most important 
means by which the growth and development of bacteria can 
be controlled. The range of temperature at which bacterial 
growth can occur may be placed between freezing-point and 






Fig. 7. — a, single bacterium; h, progeny resulting from the growth of a bac- 
terium during 24 hours in milk at 50° F. ; c, progeny of a bacterium 
during 24 hours growth in milk at 70° F. At 50° F. multiplication was 
5-fold. At 70° F. the multiplication was 750-fold. (Bui. 26, Storrs, Conn.) 

a Httle above 110° F. The growth of bacteria at these ex- 
treme temperatures is very slight. Even at 50° F. the rate 
of growth is very slow. According to experiments conducted 
by Dr. Conn, the multiphcation of bacteria at 50° F. was 5- 
fold. while at 70° F. the multiplication was 750-fold. The 
following table shows the number of bacteria per cubic centi- 
meter in milk kept at different temperatures:* 



No. at 
Outset. 


In 12 
Hours 
at 50°. 


In 12 
Hours 
at 70°. 


In 50 
Hours 
at 50°. 


In 50 Hours 

or at Time of 

Curdling 

at 70°. 


No. of 
Hours be- 
fore Curd- 
ling at 50° 


No. of 
Hours be- 
fore Curd- 
ling at 70°. 


46,000 
47,000 

50,000 


39,000 
44,800 

35,000 


249,500 
360,000 

800,000 


1,500,000 
127,500 

160,000 


512,000,000 
792,000,000 
36 hours 
2,560,000,000 
42 hours 


190 
289 

172 


56 
36 

42 



* Bull. 26 Storr's Stn., Cona 



FERMENTS IN MILK. 47 

All bacteria do not have the same optimum growing tem- 
perature. Some species develop most rapidly at one tempera- 
ture, while other species prefer a different temperature for the 
greatest development. It is on this account that certain tem- 
peratures are employed in ripening of starters and cream. 
According to researches by Conn, Bacillus ladis aerogenes 
develops very rapidly in milk at 95° F. It produces much gas 
and an unpleasant flavor in the milk. This particular species 
sours milk very rapidly. As a rule, milk which has been held 
at this high temperature, contains a preponderance of this 
undesirable species of bacteria. At 77° F. results are more 
uncertain. The species of bacteria which will predominate in 
milk at this temperature depends in large measure upon the 
number of each kind present. According to Conn, Bacillus 
lactis acidi has the highest relative growth at about 70° F. 
This particular species produces no gas, and is desirable to have 
present in cream for butter-making. Milk kept at this tem- 
perature will, in most cases, providing it has previously been 
properly treated, develop a pleasant acid taste, will curdle into 
a smooth uniform coagulum, and will contain a preponderance 
of the species of germ mentioned above. 

At as low a temperature as 50° F. acid-producing types of 
bacteria do not develop very well. But Conn maintains that 
at this temperature miscellaneous species of bacteria develop 
that produce unfavorable results. While milk does not easily 
sour at this temperature, it should be remembered that un- 
desirable germs are constantly developing. 

As it is practically impossible to exclude' all of the bacteria 
from milk during milking and the handhng of the milk, it 
is very essential that the multiplication of the germs present 
be checked, or at least retarded; and this can be done by 
controlhng the temperature of the milk. As low temperature 
is effective in checking the multiphcation of the bacteria, the 
sooner the milk can be cooled after it is drawn, the better it is 
for the keeping quality of the milk. 

Moisture. — Moisture is one of the essentials for bacterial 



48 BUTTER-MAKING. 

growth. As milk is composed largely of water, bacteria find in 
milk a good medium for growth. All the other required food 
elements are also found in abundance in milk. Damp utensils 
and rooms are always more conducive to the growth of germs 
than are utensils and rooms which are thoroughly dried and 
ventilated. This is well illustrated by a refrigerator. A very 
damp dark refrigerator is always more conducive to the growth 
of molds in butter than is a dry refrigerator. 

Unfavorable Conditions for Bacterial Growth. — The reverse 
of the favorable conditions mentioned above would be un- 
favorable to the growth of bacteria. As it is practically im- 
possible to make conditions unfavorable for the growth of 
bacteria by taking away food, other means must be used. 
Extremely high temperatures destroy bacteria. Low tem- 
peratures check their growth, but so far as known do not 
destroy them. Absence of moisture and presence of direct 
sunlight are conditions which are not conducive to bacterial 
growth. Certain chemical substances when added to milk, or 
to the medium in which the bacteria are present, are very un- 
favorable to their growth. Some of these chemicals entirely 
destroy all germ life when added in even very small quantities. 
These are called disinfectants (formaldehyde, corrosive subli- 
mate, etc.). Other chemicals are more mild in their effect upon 
germ growth, and merely inhibit or retard the growth of micro- 
organisms. The chemicals which have this milder effect upon 
germs are called antiseptics. Boracic and saHcyhc acids are 
examples. Practically all disinfectants are violent poisons, and 
should not be used in any quantity or in any form in milk 
or dairy products which are intended for human food. The 
milder preservatives, or the antiseptics, are, as a rule, not so 
poisonous or injurious to human health. In some countries 
they are allowed to a small extent. For instance, according to 
reports, the laws of England permit the use of boracic acid to 
the extent of 0.5 of one per cent. It is, however, safest not to 
use any of these chemicals, except for preserving samples for 
analytical or similar purposes. As low and high temperatures 



FERMENTS IN MILK. 



49 



are so effective in producing unfavorable conditions, these should 
be chiefly employed in controlling the growth of micro- 
organisms in the dairy industry. 

Kind of Germs Found in Milk.^ — The number of species of 
germs found in milk has not yet been definitely established, 
due chiefly to the fact that it is in some instances difficult 




Fig. 8. — Shows a plate exposed in pasture where air must ha-\^e been very- 
pure and free from germs. (Bui. 87, Nebraska.) 

for bacteriologists to differentiate one species from another. 
The description of one species of bacteria by two different bac- 
teriologists may vary considerably, as the characteristics of 
the germs depend so much upon the conditions throughout 
the classification process. Over 200 different species have 
been described. It is possible, however, though all of these 
types may have different morphological and physiological 
characteristics as described by different bacteriologists, that 
some two or more of the 200 types may belong to one species. 



50 



B UTTER-MAKING. 



For this purpose, it is sufficient to classify the bacteria into 
three groups; viz., (1) those which are harmful to the butter- 
making industry, (2) those which are beneficial, and (3) those 
which are indifferent, or produce neither good nor bad results. 

From the farmer's or milk-producer's standpoint, none 
of these bacteria are desirable. Each milk-producer should 




Fig. 9. 



-Shows a plate exposed one-half minute under a cow's udder treated 
with a 5% solution of carbolic acid. (Bui. 87, Nebraska.) 



make it a point to prevent their entrance and suppress their 
development in milk and cream to as great an extent as pos- 
sible. The creamery operator should endeavor to suppress 
all of the harmful germs, and foster the development of the 
desirable ones. 

The germs which are desirable belong chiefly to the acid- 
producing types. The}^ are often called lactic ferments. 

The harmful bacteria include those which produce bitter 
milk, red milk, blue milk, yellow milk, slimy milk, etc. There 



FERMENTS IN MILK. 



51 



is a number of species belonging to this group. The patho- 
genic germs, or (Usease-producing bacteria, must also be classed 
with the harmful bacteria. It is not the intention in this 
work to give an extended discussion of this sul)ject. For 
such discussion see special works on Dairy ]3acteriology. 




Fig. 10. — Shows plate exposed one-half minute under cow's udder treated 
by merely brushing with the hand; each little spot represents a colony 
of some kind of bacteria. (Bui. 87, Nebraska.) 



Number of Bacteria in Milk. — The number of bacteria 
found in milk varies so much that it is practically impossible 
to state accurately the average number. The number of 
germs found varies according to several conditions, such as 
degree of cleanliness of cows, utensils, and milker; degree of 
purity of the atmosphere when the cows are milked; and 
the temperature at which the milk is kept. When the milk 
is being produced under the best practical sanitary conditions, 
the number of germs need not exceed 10,000 per c.c. Such 



52 BUTTER-MAKING. 

results cannot be obtained unless extreme precautions are 
taken. Milk produced under average farm conditions sel- 
dom contains less than 50,000 germs per c.c. shortly after the 
milking. Milk which is produced under filthy conditions, 
and which is several hours old, may contain several millions 
of bacteria per c.c. 

Sources of Bacteria in Milk. — Except in the cow's udder 
where they are present to only a small extent, bacteria are 
present almost everywhere. They float in the atmosphere 





--^^ 

Fig. 11. — The wrong and the right kind of a milk-pail, a, the ordinary- 
type of pail showing sharp angle between sides and bottom; B, the same 
properly flushed with solder so as to facilitate thorough cleaning. The 
lower figure represents a joint as ordinarily made in tinware. The de- 
pression a affords a place of refuge for bacteria from which they are 
not readily dislodged. This open joint should be filled completely with 
solder. (From Bui. 62, Wis.) 

and adhere to particles of dust. Especially is this so in the 
dusty cow-stable. They are present in all well water to a greater 
or less extent. They are very abundant in streams and rivers. 
They are present in the soil to a depth of several feet, the 
number decreasing with the depth. As these germs are prac- 
tically present everywhere, the source of germs in milk may 
be said to be all around us. The principal sources of germs 
in milk are, however, unclean dairy utensils, unclean cows, 
and unclean surroundings. As these germs multiply chiefly 
by fission, or by one cell dividing into two, it is plain that the 
number of germs will increase very rapidly under favorable 
conditions. Under the most favorable conditions it requires 



FERMENTS IN MILK. 53 

approximately twenty minutes for this process of fission to 
take place. 

Some germs develop small bodies within the cell, called 
spores. It is not difficult to destroy the sporeless cell by 
heat, but the spores are very resistant to unfavorable con- 
ditions. The spore-bearing bacteria cannot be destroyed by 
boiling. The heating destroys the vegetative cell, but the 
spores still remain. In order to destroy the germ in the spore 
form, it is essential that the milk be cooled to a temperature 
favorable to growth, and then allow the spore to develop into 
a vegetative cell. If heat is again applied, the milk can be 
rendered entirely sterile. Usually three or four successive 
heatings and coolings are necessary in order to render the milk 
completely sterile. A single heating under pressure (15 minutes 
at 15 pounds) kills them at once. 

It has been demonstrated by several investigators that 
freshly drawn milk is not a good medium for bacteria to develop 
in. In fact, several experiments seem to indicate that milk 
acts as a germicide to certain varieties of bacteria. For instance, 
the cholera germ is to some extent destroyed in fresh milk, 
but it is not known to what extent. Organisms producing 
lactic acid check the multiplications of these pathogenic bac- 
teria. This germicidal property is said to be common, to a 
greater or less extent, to all the animal secretions. 

Effect of Thunder-storms on Souring of Milk. — It is a common 
impression that thunder-storms hasten the souring of milk. 
This was attributed to the electricity in the air accompanying 
the storm. Experiments by several investigators have proved 
that electricity does not have any effect on hastening the fer- 
mentative changes of milk. The reason why milk sours quicker 
when an electrical storm is approaching, is that the air tem- 
perature is usually higher then than at any other time. This 
higher temperature warms the milk and creates more favor- 
able conditions for the rapid multiplication of the germs present 
in the milk. It is for this reason that milk sours quicker during 
or previous to a thunder storm than at any other time. 



CHAPTER V. 

ABNORMAL MILK. 

Colostrum Milk. — Colostrum is the milk yielded immediately 
after calving. As the time of calving approaches, a cow usually 
diminishes in her milk-producing capacity. Most cows become 
dry about two months previous to parturition. If they do not 
naturally stop giving milk, they should be dried up so as to have 
a seven week's rest before calving. When the rest has been 
given, the cows yield, immediately after calving, milk which has 
a composition and characteristics different from those of normal 
milk. If the cow continues to give a copious flow of milk up to 
the time of calving and is not allowed any rest, the difference 
in the milk yielded before calving and after calving is compara- 
tively slight. 

The composition of colostrum varies considerably during the 
first three days after calving. According to Engling, as reported 
by Richmond, the composition is a follows: 

Water 71.69% 

Fat 3.37 

. . , f Casein 4 . 83 

Albummoids-I .„ -.r or 

[ Albumen lo . 85 

Sugar 2.48 

Ash 1.78 

Colostrum greatly changes in composition and appearance 
as it gradually assumes the characteristics of normal milk. It 
is at first reddish yellow in color, and has a viscous and slimy 

54 



ABNORMAL MILK. 55 

consistency. It is a food which the newly bom calf should not 
be deprived of, as it seems to be specially suited for the digestive 
tract of the young calf. 

It ^^ill be seen from the above table that the water content 
of colostrum is less than that of normal milk. The fat content 
is a ittle lower than that of normal milk. The most striking 
characteristics of colostrum, however, are the low content of 
sugar, and the large amount of albumen. Of the latter substance 
very little is present in normal milk. The mineral constituents 
of colostrmii also run quite high. The specific gravity of 
colostrmn varies from 1.046 and 1.079. TMien boiled, the 
nitrogenous matter coagulates. The colostrum is not considered 
to be suitable for food until about four days after parturition. 
TMienever it can be boiled without coagulating, it is claimed 
to be safe to use. At tunes a cow's udder becomes inflamed 
after calving. In such cases the abnormal qualities of the 
cow's milk "^ill extend over a greater period of time than that 
mentioned above. 

Salty Milk. — The average chemical analysis of salty milk as 
calculated from results obtained b}' the analysis of such milk 
from four cows given by Boggild,* is as follows: 

Water 91.09 

Fat 2.09 

Nitrogenous matter 2 . 90 

Sugar .3.01 

Ash -.85 

It has an average specific gravity of 1.0244. 

Salty milk does not occur very often, but whenever it does 
occur, it is difficult, and, so far as known, impossible to cure 
"without dr^-ing up the cow. Two samples of such milk have 
recently come within the author's notice. It had the appear- 
ance of normal milk, had a foul smell, and very salty taste. 

* Maelkeribniget in Deninark. 



56 BUTTER-MAKING. 

The two samples contained 1.7% and 1.9% of fat respectively. 
They soured and curdled in a normal way at living-room tem- 
perature in about thirty hours. At this stage they were very 
foul in smell, and unpleasant in taste. 

The cows which had produced this milk had both calved 
about three months previously. It occurred in the month of 
July, when pastures were quite good. The udders of the cows 
were in an apparently normal condition. At first it was thought 
that some conditions in the pasture caused this abnormal milk. 
The cows were taken into the barn, and fed on dry food for 
two weeks, but without any change in the equality of the milk. 
Gradually they dried up. 

The reason for the secretion of this salty milk was laid to 
the long time which the cows had been yielding milk without 
any rest. They had been given no rest previous to the last 
calving. It is also believed that this quality of milk will occur 
more frequently when the cows are near the close of their 
lactation period. 

While the above two causes are perhaps the most common, 
they are not the only ones. Salty milk has been obtained from 
cows to which these reasons could not be ascribed. Boggild has 
found that salty milk has been secreted by cows with abnormal 
udders. He has also demonstrated that it was the diseased part 
of the udder from which the salty milk was yielded. The healthy 
portion of the udder yielded normal milk. It is possible that 
an obscure, diseased condition of the udder may be the entire 
cause. 

Salty milk is of course undesirable in the dairy or creamery. 
It is very disagreeable to the taste, and in a fermented stage 
becomes very foul. 

Bloody or Red Milk. — Bloody, or red milk is caused, first, 
by an abnormal condition of the cow's udder, which may or may 
not be apparent; and second, a red color may be developed in 
milk after standing, through the action of bacteria. 

The bloody milk, caused by an inflamed udder, often assumes 
a reddish-yellow appearance, and may, if not examined care- 



ABNORMAL MILK. 57 

fully, be mistaken for colostrum. Bloody milk produced by an 
inflamed udder, may be distinguished by noticing small blood 
particles, which will settle to the bottom, and can be noticed if 
the sample is placed in a glass test-tube. Bloody milk caused by 
bacterial growth does not show^ the blood at the bottom, but 
instead, previous to stirring the milk or cream, it appears on 
the surface in small red dots. The red color which commonly 
occurs in milk is due chiefly to a species of germ called Micro- 
coccus prodigiosus. Colostrum will show reddish cream on the 
surface, but no blood-like material will separate out. 

Blue Milk. — Blue milk is quite commonly found. Formerly 
it was thought that this color was due to the condition of the 
casein in the milk, but since more has been discovered in regard 
to the effect of germ hfe upon conditions and properties of milk, 
it has been proved that blue milk is caused by bacteria* (Bacil- 
lus cyanogenus). This particular germ produces the blue color 
in the milk only ^^•hen the milk has an acid reaction. AVhen 
sterile milk is inoculated with this particular germ, the blue 
color is not produced, but by the addition of a little acid, or by 
inoculating the milk with the bacteria that produce lactic acid, 
the blue color is produced. This seems to be one of the instances 
of symbiotic action of bacteria in milk. There are probably 
other causes, but they are not known. This germ, according 
to Aikman, is killed by heating the milk to about 176° F. The 
germ ceases to work as soon as milk is coagulated. 

Yellow Milk. — According to Aikman,* yellow milk is caused 
chiefly by one species of bacteria, named Bacillus synxanthus. 
This micro-organism belongs to the group of ferments that act 
upon the fat of milk. There are different shades of yellow 
produced in milk, caused by different species of bacteria, but 
the above-mentioned one is considered to be the principal cause. 
Some produce a brilliant yellow color, while other species first 
curdle the casein, and then digest or dissolve it into a yellow 
or amber-colored hquid. 

* C. M. Aikman, in "Milk, Its Xature and Composition." 



58 



BUTTER-MAKING. 



Ropy Milk.— The slimy or ropy condition of milk is not 
common. It is sometimes found in milk handled by milk- 
dealers and is caused by certain micro- 
organisms. Aikman mentions the fact that 
no less than eighteen different distinct organ- 
isms have been identified as associated with 
this slimy fermentation. Most of the inves- 
tigators agree that two organisms are chiefly 
responsible for this slimy condition. One of 
these is Bacillus lactis viscosus.^ This germ 
has been found to be frequently present in 
surface waters. The very fact that milk- 
dealers in cities are occasionally troubled with 
this sliminess in milk indicates that precau- 
tions are essential in order to avoid the pres- 
ence of this ferment in milk. This germ, when 
it once gains entrance to a milk establishment, 
is very difficult to eradicate. In order to 
overcome this trouble it may be necessary 
to cover the w^hole inside of the milk-store, 
and all of the vessels used for handling the 
milk, with sour coagulated milk. The lactic 
acid germs present in this milk gains ascend- 
^^^.■„ 1 2 . -- Slimy ei^cy over the germs causing sliminess, and 

milk; this milk -, i i i , 

would "string m that way the trouble may be eradicated. 

se^'veral^^'feet'^^^fn Streptococcus hollandicus f is another spe- 

length. (From Bui. cies whicli produces sliminess in milk. This 

particular organism is used in Holland as a 

starter. The starter containing this particular germ is added 

to the milk used in the manufacture of Edam cheese, in order 

to control or check the gassy fermentation which may be present 

in it. 

Bitter Milk. — This is one of the most common kinds of 
abnormal milk, and like some of the others, may have more 

* Adametz Landw. Jhr., 1891, p. 185. 
t Milch Zeit., 1889, p. 982. 



60 BUTTER-MAKING. 

than one cause. It may be due to some undesirable food that 
the cow has eaten, or to the development of certain germs in 
the milk. If caused by the food eaten by the cow, the bitter 
taste is recognizable immediately after the milk has been drawn. 
If it develops on letting the milk stand, it is caused by bac- 
terial growth. 

Several germs have been found to be associated with the 
production of this bitter flavor in milk. Conn has described a 
micrococcus which produces a bitter flavor in milk. Weig- 
mann has described a bacillus which also produces bitter 
flavors. Nearly all of the investigators agree that the germs 
causing the bitter flavors in milk belong to the group which acts 
upon the casein in milk. The bitter flavor is most commonly 
found in milk that has been heated, and then cooled to a low 
temperature. The heat destroys the bacteria that produce 
lactic acid, but does not kill those that produce the bitter 
flavor, owing to the fact that they are spore-producing. 

The germs that produce a bitter flavor do not develop in 
milk that is partly soured, because an acid reaction is un- 
favorable to their growth. 

It was formerly thought that the organisms that cause the 
bitter flavor in milk produced butyric acid. This theory, 
however, has been largely overthrown, as it has been found that 
the germs causing bitter flavor are chiefly of the kind which 
peptonize the casein and produce gas. 

Milk from Cows which have Been in Milk for a Long Period. 
— The difference in the composition of the fat yielded by cows 
in different stages of the lactation period seemingly does not 
affect the quality of the milk to a noticeable extent. If the 
cows have been giving milk an unusually long time, then the 
milk may become abnormal. 

The impurities in the small amount of milk yielded by cows 
almost dried up are quite apparent, and the causes of the 
presence of these impurities are readily understood. The 
small amount of milk drawn from such a cow would contain 
a proportionately larger amount of dirt and germs than would 



ABNORMAL MILK. 61 

a larger amount of milk drawn from a cow yielding more milk, 
providing the cleanliness of the udder and manner of milking 
were the same. Cows giving a good quantity of milk always 
seem to have a cleaner udder. This has been laid to the more 
vigorous circulation of the blood in the udder of the cow that 
yields a larger portion of milk. 

When cows calve once a year, and have rest of about seven 
weeks previous to parturition, if proper precautions are taken 
concerning cleanliness, they seldom yield milk from which a 
first-class quahty of butter cannot be produced. In practice 
this regularity of calving does not always exist. Several in- 
stances have come within the author's notice where cows have 
been in milk for two years or more without coming in fresh. 
Such a condition happens quite frequently on small farms, 
where the cows kept are so few that it is deemed imprac- 
ticable to keep a bull. As a consequence cows are not 
served at the proper time, and great irregularities in calving 
are introduced. 

At times it also happens that cows become barren. In 
such a case they are usually milked as long as they will pro- 
duce even a very small quantity of milk. Milk produced under 
such conditions is likely to become abnormal in character. 
It may remain normal with a slight increase in the fat-content. 
The abnormal milk, so often complained of, is usually brought 
about by similar circumstances. It is a common belief that 
milk yielded from such animals always contains a high fat- 
content, but it may contain very httle fat. It may be salty. 
It may also appear normal, and the cream when separated 
appear viscous and dead. Boggild states that the milk at the 
creamery from one barren cow has more than once pro- 
duced difficult churning. 

Milk from Spayed Cows. — H. Lennat has given this kind of 
milk considerable study. He finds that milk from spayed 
cows may vary in quality to the same extent as milk from normal 
cows. The solids of milk, as a rule, increase as the spayed 
cow advances in the milk-giving period. Especially was this 



62 BUTTER-MAKING. 

noticeable in the fat, sugar, and casein. Such milk is con- 
sidered to be of extra good quality, and is recommended as 
being especially suitable for infant-feeding. 

Milk from Sick Cows. — Too much cannot be said against 
the use of milk from sick cows. As soon as the cows decline 
in health, the quantity will be noticeably decreased, and the 
quality is usually abnormal. The kind of milk yielded varies 
with different cows and different diseases, but it is interesting 
to note from the study of this subject, by several men, that 
the milk-secreting glands are quickly affected by disease and 
are unable to perform their proper functions. Even a slight 
derangement of the digestive organs is said to have a marked 
influence upon the flavor of the milk and butter. When cows 
do not clean well after calving, the milk secreted by them 
always has an undesirable taste. During the time of sexual 
excitement of the cow, milk is usually decreased in quantity, 
and in a great many instances assumes a very disagreeable flavor. 

When a cow's udder is inflamed, the milk usually assumes 
an abnormal condition. It usually contains large, white, 
slimy lumps. According to Bang,* this is caused by a small 
round bacterium, and is contagious. When this germ is in- 
oculated into the udder, the cow gets feverish and the milk 
becomes slimy. 

When cows become infected wdth tuberculosis to such an 
extent that the udder shows lesions and nodules, then the 
composition and appearance of the milk is altered consider- 
ably. Milk from such cows contains tubercle germs, appears 
yellowish brown in color, and has an alkaline reaction. The 
composition of such milk has been studied in Denmark and 
reported by Boggild to be as follows : 

Water 88.79 

Fat 3.55 

Albuminoids 5 . 69 

Sugar 1 . 25 

Ash 94 

* Maelkeribruget i Danmark, by Boggild. 



ABNORMAL MILK. 



63 




Fig. 14. — The carcass of an animal killed for beef, showing tuberculosis of 
the liver, omentum, and lungs. Generalized tuberculosis. (Bui. 229, 
CorneU, N. Y.) 



64 BUTTER MAKING. 

These results represent the average of four samples taken 
from the diseased part of the udder. It will be seen that the 
greatest variation from normal milk exists in the small amount 
of sugar it contains and the high per cent of ash and nitrog- 
enous matter. 



CHAPTER VI. 

VARIATION OF FAT IN MILK. 

The percentage of fat in normal milk varies a great deal 
more than any other of the constituents of milk. Dr. Rich- 
mond reports that the fat of milk may go as low as 1.04% and 
as high as 12.52%. Such extreme variations are, of course, 
abnormal. The fat-content seldom falls below 2^% or rises 
above 7%. The fat-content of milk from a whole herd of 
cows, varies only within comparatively narrow limits. The 
following are the chief factors which cause the fat-content 
of milk to vary: 

(1) Individuality of cows. 

(2) Breed of cows. 

(3) Time between milkings. 

(4) Manner of milking. 

(5) Whether the milk is fore or after milk. 

(6) Age of cow. 

(7) Lactation period. 

(8) Feed of cows. 

(9) Environmental conditions. 

I. Individuality of Cows. — That the quantity of milk from 
individual cows varies is a fact that is well known to every- 
one who keeps cows, but the average cow-keeper does not very 
well apprehend that the percentage of fat is as variable a factor 
as it really is. As a rule, when a cow yields only a small quantity 
of milk she is in many instances condemned without taking 
the quaUty into consideration. If the fat content were taken 

65 



t)6 BUTTER-MAKING. 

into consideration, such a cow might prove more profitable 
to keep than another that yields a larger quantity of milk. 
For this reason the yield of fat is a better standard by which 
to judge the value of a cow than the quantity of milk. Since 
the general introduction of the Babcock test for the deter- 
mination of fat in milk, the fat-content of milk can be easily 
determined, even on the farm. The importance of testing 
the milk of each cow in a herd is sufficient to warrant every 
cow owner to have a complete Babcock testing outfit on the 
farm. 

Unprofitable cows are, and have been, a serious draw- 
back to dairy progress. According to Dairy Commissioner 
Wright's reports, the average yield of butter per cow, in the 
State of Iowa, is less than 140 pounds per year. Some of the 
cows from which these statistics were calculated evidently 
gave good returns to the owners, while others again would 
run their owners in debt. Cases are on record where single 
cows have produced more than eight hundred pounds of butter 
annually. Such a yield is the result of a great many years 
of attention to the selection and breeding, and can be obtained 
only in special cases. A yield of 400 pounds of fat per cow 
annually might be a good standard for which to strive. Even 
if the average annual butter yield per cow could be brought 
up to 300 pounds, the dairy industry would be put on a sounder 
and more profitable basis. The average price of butter is 
about twenty cents per pound. At this rate 300 pounds of 
butter would be worth $60.00. The average cost of keeping a 
cow in the State of Iowa is about $35.00, including care and 
feed. This would leave a net profit of $25.00 per cow. If 
a cow yielded only 140 pounds per year, which at 20 cents 
would be worth $28.00, the owner of that cow would suffer 
a loss of $7.00. It must not be forgotten that the above cal- 
culation is based only upon the butter-fat. The calf and the 
skimmed milk are not taken into consideration. The skimmed 
milk is worth 25 cents per hundred pounds for feeding pur- 
poses, and the calf is worth about $3.00. 




Guernsey Cow (Custer's Belle, 9514). 
Owned and bred by W. D. Hoard, Fort Atkinson, Wis. Calved when 
two years old. She produced that year 423 pounds of butter-fat. Periodical 
weighing of milk every seventh week and testing showed that she had pro- 
duced 6(i49 pounds of milk containing 314 pounds of fat in eight months 
ending Sept. 14, 1905. She calved again Jan. 15, 1905. The above records 
we- e made under ordinary feeding and management such as the whole herd 
received. 



VARIATION OF FAT IN MILK. 67 

Table by Gurler, Showing Records of Individual Cows. 






IS 



Av. of 
50 cows 

244 

154 
44 
72 

308 

184 

262 

283 

129 
Av. of 4 

best 
Av. of 4 
poorest 
Av of 9 

cows 



5708 
2382. 
3619 
3399 
2661 
4617 
7997 
9297 
10151 
8449 

9098 

3020 

5897 



1.47 
4.87 
4.51 
4.58 
5.06 



4.25 
4.75 
4.43 



255 
116 
163 
155 
134. 
177, 
382, 
372. 
374. 
406. 






384 . 00 
142.60 
253.5 



297, 
135. 
190. 
181. 
157. 
206. 
445 . 
434. 
436. 
472. 



447 . 32 
160.40 

295.7 






j3 C 



54 5453 
09 2266 
1213494 
863243 
492526 
43 4440 
147615 
9318900 
3519777 
43 8545 



89.4618709 

33.28 2881 



o c 
£ S 



.00 
.66 
.64 
.10 
.31 
.03 
.14 
.00 
.44 
.36 



21.76 
7.20 



"°M 



73 
32 
46 
44 
37 
52 

108, 

109. 

111. 

115. 



111.22 
40.48 



41.06 

31. :3 

41.06 
37.32 
26.45 
39.32 
44.32 
44.72 
44.72 
46.06 

44 . 95 

33 . 96 



59.14L5644 14.il 73.25 39.46 



+ I 



+ 19.98 
-11.00 

- 6.80 

- 5.34 

- 1.15 
+ 0.44 
+ 51.46 
+ 51.80 
+ 54.57 
+ 57.24 

+ 53.77 

- 5.98 
+ 21.25 



In making the calculations in the above table the price of 
butter per pound was taken as 20 cents, the skimmed milk 
was considered to be worth 25 cents per hundred pounds, and 
the cost of labor was taken at $12.50 per cow. 

Breed of Cows. — There is a marked difference in the milk 
secreted by different breeds of cows. The most striking differ- 
ence is, perhaps, between the Holstein and the Jersey breeds. 
The former, as a rule, yields a large quantity of milk, with a 
comparatively low fat-content; the latter, as a rule, yields 
a comparatively small quantity of milk, with a high per- 
centage of fat. The influence of individuality of cows must 
not be overlooked in this connection. 

It is said that the color of the skin, and of the fine hairs on 
the exterior of the cow's udder may be taken as a guide in 
selecting cows for breeding purposes. A fine soft skin, darkish 
golden yellow in color, enveloping the milk -glands, and covered 
with fine soft hair, are considered indications of rich milk. 
While the Jersey cows perhaps yield milk with a higher fat- 



68 



BUTTER-MAKING. 



content than any other breed, a high percentage of fat is char- 
acteristic of the milk from ah the Channel Island breeds. On 
account of the great variation in the composition of milk from 
different cows, it is difficult to get results from experiments 
where the number of cows involved in each breed and trial 
have been so numerous as to overcome the individuahty of 
the cow. We quote the following table, which shows the 
average results from the breed tests conducted at the Annual 
Dairy Shows of the British Dairy Farmers' Association between 
the years 1879 and 1893, inclusive: 



Total 
No. of 
Ani- 
mals. 



147 

i:9 

63 
10 

18 



1 
1 

12 

30 



Breed. 



Shorthorn. . . . . . 

Jersey 

Guernsey 

Holstein. 

Ayrshire 

DeA'ons 

Red Polls 

Welsh. 

Aberdeen-Ang. . 

Kerries and 

Dextefs. . . . . . 

Crosses. 



Average 
Milk 
Yield. 
Lbs. 
Daily. 



43.86 
27.36 
28.95 
45,19 
37.82 
30.12 
35.10 
46.00 
60.30 

26.59 
42.05 



Total Solids. 



Per 
Day, 
Lbs. 



5.64 
3.98 
4.07 
5.53 



3.56 

5.41 



Per 

Cent. 



12.86 
14.54 
14.05 
12.25 
13.45 
14.34 
12.96 
12.74 
13.74 

13.37 

12.87 



Fat. 



Per 
Day, 
Lbs. 



1.65 
1.33 
1.38 
1.54 
1.60 
1.48 
1.38 
1.91 
3.01 

1.11 
1.56 



Per 

Cent. 



77 
85 
78 
41 
22 
90 
92 
16 
99 



4.18 
3.70 



Solids, 

Not 

Fat, 

Per 

Cent. 



9.09 
9.69 

9.28 
8.84 
9.23 
9.44 
9.04 
8.58 
8.75 

9.19 
9.17 



Live 
Weight. 



1403 
832 
1033 
1383 
1060 

1201 



749 
1362 



These results agree very closely with tests carried on in 
the United States, with the exception of the two breeds, Welsh 
and Aberdeen Angus. The former breed is rare in this country. 
The latter breed is considered to be quite inferior as a milk- 
producing breed, but one of the best beef types known. The 
results obtained in the test above, where only one cow w^as 
involved, are abnormal and cannot represent the average of 
Angus cows' milk. 

Time Between Milkings. — The common practice in the 
United States is to milk twice during twenty-four hours, every 
morning and evening. The intervals between these milkings 
are not always of the same length. Under the average farm 




HoLSTEiN Cow (Shady Brook Gerbin, 43753, H. F. H. B.). 
Property of M. E. Moor, Cameron, Mo. Record at St. Louis Exposi- 
tion, June 16 to Oct. 13, 1904, (120 days,) 8101.7 pounds of milk containing 
282.6 pounds of fat. Value of feed consumed $36.57. Dropped in June, 
1892. Weight 1319 pounds. 



VARIATION OF FAT IN MILK. 



69 



conditions the cows are milked in the morning about 5 o'clock, 
and in the evening about 7 o'clock. This is especially true 
during the spring and early summer months. This long interval 
during the day causes the cow to give a greater quantity of 
milk in the evening, but it contains a smaller per cent of fat. 
The recent results obtained by Ingle illustrate this point very 
plainly. Five cows were milked at 6 a.m. and at 3 p.m. during 




Fig. 15. — The wrong way to milk cows. (From Glucose Sugar Refinmg 

Catalogue.) 

a period of three weeks. The average fat-content of the eve- 
ning's milk was 4.26% and of the morning's milk 2.87%. 
During the four weeks following the same cows were milked 
at 5.30 A.M. and 5 p.m. The fat-content of the evening's milk 
was 3.80%, and of the morning's milk 3.18%. It is main- 
tained, and the above results indicate the same, that even 
if the intervals between milkings are equal, the morning's 
milk will contain slightly less fat. This is accounted for by 
the theory that the fat-secreting cells are more active during 
the day, when the cow is exercising. 



70 BUTTER-MAKING. 

It is customary in Denmark, and in other countries where 
dairying is practiced extensively, to milk three times a day, 
early morning, noon, and late at night. The only reason that 
can be assigned for getting richer miik after the shorter in- 
terval is that the distension caused by the excess of milk in 
the udder retards or restrains the free activity of the fat-secreting 
cells in the mammary glands. Experiments also show that 
frequent milking gives a greater quantity of milk. The in- 
crease, however, is not great enough to induce the average 
dairy farmers in America at the present time to milk more 
than twice daily. The intervals between milkings, however, 
can, without any special outlay of money or time, be equalized. 

Manner of Milking, — The milk should in all cases be drawn 
as rapidly as possible, and in such a way as to cause no dis- 
comfort to the animal. The hand and fingers should be used 
in such a way as to imitate nature's method as closely as pos- 
sible. When the hand is placed around the teat, the upper part 
of the hand, or the thumb and forefinger, should close around 
the teat first, then the others closing gradually as the milk 
is pressed out. The fingers should encircle the teat without 
inserting the nails and causing discomfort to the animal. The 
Hegehmd method of milking, in comparison with the ordinary 
method, has been investigated by Woll, and the results ob- 
tained were m favor of the former. 

The Hegelund method consists of manipulating the udder 
and parts of the udder in a systematic and regular way by 
lifting and pressing the different quarters of the udder. In 
the Wisconsin University herd of 24 cows, with which Dr. 
Woll experimented, the quantity of milk was increased by 4.5% 
and the quantity of fat by 9.2%, by the use of the Hegelund 
method. 

Milking-machines. — For a long time successful milking- 
machines have been expected by dairy enthusiasts, but so far 
no machine is on the market which promises to do work that will 
warrant its permanency in dairying. If any machine has 
been perfected which gives entire satisfaction, it is not within 




Jersey Cow (Loretta D, 141,708, A. J. C. C). 
Owned by W. S. Ladd, Portland, Oregon. Record at St. Louis Expo- 
sition from June 16 to Oct. 13, 1904, (120 days,) 5802.7 pounds of milk con- 
taining 280.16 pounds of fat. Value of feed consumed $31.99. Dropped 
Oct. 13, 1893. Weight 1075 pounds. 









Fig. 16. — First manipulation of udder, right Fia. 17. — First manipulation, left quarters, 
quarters. 




Fig. 18.— Second manipulation, right fore-quarter. 





Fig. 19. — vSccoiid niaiupulatioii, right hind- Fig. 20. — Third manipulation. 

(liiaiter, rear \ ie\\ 
Illustrating Hegelund method of milking. (From Report of Kansas State Board 
of Agriculture, No. 87, 1903.) 

71 



72 



BUTTER-MAKING. 



the knowledge of the authors. Many attempts have been 
made, and some of the machines now on the market seem to 
be close to practical success. The "Thistle" milking-machine 
was for some time considered a success. The " Sharpies Pul- 
sating Lactator" is seemingly meeting with some success. 
The Devore-Hoover Cow Milker Co., Waterloo, Iowa, has 
perfected a machine for which great claims are made. 




Fig. 21. — De Schmidt milking-machine. 

All of the above machines are represented by their re- 
spective inventors and manufacturers to do successful work, 
but none of them are yet advertised entensively, which seems 
to indicate that some points are yet lacking before they can 
be successfully operated in practice. Whether a milking- 
machine will ever be perfected which can imitate natures 
methods as closely as the human hands, is a question which 
has yet to be solved. 




An Unregisteked hut Plike-hueu Ayrshire Cow. 
Owned by C. C. Burr, St. Charles, 111. In the year 1932-3, under ordinary 
farm conditions and feeding, .she gave 8467 pounds of milk which contained 
342 pounds of butter-fat. 



VARIATION OF FAT IN MILK 



73 



According to experimental evidence, milk drawn with a 
machine contains more bacteria than milk drawn by hand. 
This is claimed to be due to the suction on the exterior of the 
teat, and to the tubes through which the milk must pass after 
it is drawn. 

Fore-milk and After-milk. — The fore-milk, or the milk 
drawn from the cow's udder first, contains much less fat than 
does the milk drawn subsequently. The very first milk drawn 




Fig. 22. — Milking goats in Norway. 



appears watery and contains as little as 0.1% of fat, while 
the very last milk in the udder may contain as high as 12%,. 

Tire reasons assigned for this variation are (1) the milk in 
the canal of the teat, and lower portion of the milk-reservoir 
is present under such conditions as to allow creaming to proceed. 
(2) The larger fat-globules are about as large as the smaller 
milk-dusts in the cow's udder; consequently the dowmward 
passage of these fat-globules meets with some obstruction 



74 BUTTER-MAKING. 

and they are drawn out only when the last milk is removed. 
(3) The fore-milk has been subjected to a re-absorption process 
of the lymphatics. The third factor perhaps plays only a 
small part in reducing the fat-content of the fore-milk. As 
the fore-milk contains so very little fat, and a great many 
micro-organisms, it is often advantageous to reject the first 
few streams of milk. Especially is this important when sani- 
tary milk is desired. 

It is in many instances customary, in order to apportion 
the calf a certain amount of milk, to first partly milk the cow 
by hand, and send this milk to the creamery, and then allow 
the calf to suck the remainder. The results of such procedure 
are plain, yet it is practiced to a large extent. When dis- 
covered, it has in many instances explained why a certain 
creamery patron's milk has been testing low at the creamery. 

Age of Cow. — There is a time during the life of a cow when 
she is most vigorous and most productive. At the time she 
first calves (about three years old) the cow or heifer is still 
growing, and her milk-producing capacity is not so great then 
as it is later on, when she becomes matured. After this increase 
in quantity there is also a slight increase in quality. At the 
age of about seven years the cow is usually at her best. As 
the cow advances in age, usually the cjuantity and quality 
diminish. However, the individuality of cows prevents draw- 
ing any definite line. In some cows age has considerable 
effect, while in others age has but little effect. 

Lactation Period. — By lactation period we understand the 
milking period, from the time of calving until the cow is dried 
up. The first few days after calving, the cow yields milk 
which is rich in solids, not fat. The fat-content in milk from 
most cows usually increases a trifle during the first two weeks 
after parturition. Then, when conditions are normal and uni- 
form, the percentage of fat is nearly constant for about three 
months. After this time the quantity decreases and the 
quality gradually increases a trifle. This applies more fully 
if the cow is pregnant. Most cows calve in the spring of the 




Short-hohn Cow (College Moore). 
Owned by Iowa State College, Ames, la. She produced 9893.5 pounds 
of milk containing 406.8 pounds of fat during one milking period extend- 
ing over .393 days beginning Oct. 4, 1899. Weight 1695.8 pounds. 



VAPJATIOX OF FAT IX MILK. 75 

year, and as a consequence milk usually tests a little higher in 
the fall. 

Food of Cows. — For a long time it was thought that the 
kind of food had considerable influence upon the fat -content of 
milk, but later experiments in this country, as well as in foreign 
coimtries, have almost completely demonstrated that food has 
practically no effect upon the quality of milk. Investigators 
agree that foods may affect the fat -content of milk by increasing 
the quantity of milk, without reducing the per cent of fat. thus 
increasing the total amount of fat. Extensive experiments 
were carried on in Denmark, where more than one hmidred 
and fifty cows were involved in each experiment, on ten different 
estates, in order to determine the effect of food upon the per- 
centage of fat in the milk. Eoots of diff'erent kinds, which 
are very succulent, were fed with out reducing the per cent 
of fat. Different concentrated feeds (oil-cake, wheat, bran, 
ground barley, and oats ) v\-ere also fed with a \ievr of increasing 
the percentage of fat. but without any noticeable effect. The 
Xew York Station found, tln-ough carefully conducted experi- 
ments, that feeding tallow to cows did not increase the percent- 
age of fat in the milk. 

Soxlilet fomid that by feeding tallow, in the form of an 
emulsion, for a considerable time, he was able to increase the 
percentage of fat in the milk. The Iowa Experiment Station 
also reported that the percentage of fat could be increased b}^ 
feeding oil meal. Dr. Lindsey. at the Hatch Experiment 
Station. Massachusetts, recently found that fat can be slightly 
increased by the use of certain foods rich in oil. 

But on the whole, the results reached so far show that 
different foods have little influence on the percentage of fat in 
the milk. Especially is this so imder practical condi- 
tions. 

On the other hand, different kinds of foods afl'ect the compo- 
sition of the fat itself. Gluten meal, in fact all gluten products, 
produce butter containing a high percent of olein. and usually 
an increase in the volatile fats. Cottonseed-oil produces a 



76 BUTTER-MAKING. 

decrease in the volatile fats, and makes butter noticeably 
harder and more tallowy in appearance. 

Environment.— Unfavorable environmental conditions im- 
posed upon a cow, such as sudden changes in temperature, 
storms, impure surroundings, and ill-ventilated barns, are 
certain to decrease the flow of milk; and if they are continued a 
few days, the percentage of fat in the milk will decrease also. In 
a general way it might be said that any unfavorable condition 
which causes a decrease in the quantity of milk will cause a 
slight increase in the percentage of fat during the first few days. 
But if the cow is surrounded with these unfavorable conditions 
for any length of time, the percentage of fat will again decrease. 
It is possible, how^ever, by ill treatment, to diminish the fat- 
content greatly. 

Exercise, also, affects the yield of milk, as well as the c{uality. 
Uninterrupted, long confinement in a stall is detrimental to 
a cow's health. For a time it shows no effect upon the c|uan- 
tity and quality of the milk, but eventually it will decrease 
both. However, many Danish dairy farmers keep their cows 
in the barn all winter, without letting them out for exercise, 
and it is said that this confinement has apparently no effect 
upon the c|uantity and c|uality of milk. But a proportion- 
ately large number of their cows are infestetl with tubercu- 
losis. Whether this is due to lack of fresh air and exercise, the 
authors cannot say. 

Too much exercise is adverse to producing the most and 
best milk. If a cow is kept in the barn every day, half an 
hour's exercise, preferably out of doors, when weather permits, 
seems to give good results. A small box-stall for each cow, or 
a well-bedded shed for them to stand or lie dow^n in after feeding, 
are favorable conditions for getting the proper amount of 
exercise, especially during cold weather. 

Change of location, fright, sudden shocks, and nervousness 
are conditions from which the cow must be kept, in order to 
do her best as a milk-producing animal. 



CHAPTER VII. 

RECEIVING, SAMPLING, AND GRADING MILK AND CREAM. 

Receiving and Grading of Milk and Cream. — The man 

who receives and samples milk at a creamery should be 
accurate and quick with figures, have ability to grade and 
select milk, and to stimulate interest in the production of 
good milk. He should also be able to reconcile and satisfy 
patrons. The method employed in some creameries of allowing 
a boy with inmiature judgment to weigh and sample milk 
should not be tolerated. The person who weighs and samples 
milk and cream comes in direct contact with the patrons. 
Therefore, he is a strong factor in preserving the best interests 
of the creamery. In many of the best butter and cheese factories 
in the country the head maker or manager in charge is usually 
found at the weighing can. This gives him the opportunity 
of studying the raw material from which he is expected to make 
a high grade of butter or cheese. Some of our large central 
plants pay the highest salary to the man who has the ability 
to properly grade the cream and prepare the starters. This 
requires a fine sense of smell and taste, which is not possessed 
by every one. 

The first step in the receiving of milk is to ascertain the 
quality of the milk delivered by the patrons. It is now a 
recognized fact that the best butter cannot be produced from 
defective or abnormal milk or cream, no matter how many 
improved methods are employed in the manufacture. In view 
of this, and the knowledge we now have of the transmission 
of undesirable germs from one sample of milk to another, and 
also the probability that some of the patrons will deliver poor 

77 



:--S9SS?fflf^?(,V,7'fi''V' 





"^>* 



Jvffi^^^S 



. " ' ^^ , 




!jh 




RECEIVING, SAMPLING, AND GRADING. 79 

milk, it is essential that the milk or cream be graded when it 
is delivered at the creamery. 

In the grading of milk or cream, different methods can be 
used for detecting abnormal milk: (1) through the senses, 
taste, sight, and smell; (2) by the acid tests; (3) by the fer- 
mentation test; (4) by heating; (5) by the Babcock test and 
the lactometer. 

I. Detection of Abnormal Milk through the Senses. — In order 
to detect the different kinds of defective milk, one must be 




Fig. 24. — The Twentieth-century can-washer. 

endowed with acute senses of smell, taste, and sight. When 
the milk is in a good condition, it has a pleasant smell and 
sweet taste, and appears normal. If it has a disagreeable 
smell and taste it cannot produce good butter or cheese. As 
a rule, the quantity of defective milk brought into the aver- 
age creamery is much in excess of that of really perfect milk. 
As a consequence it would not be practical to separate all 
the defective milk into one class and the perfect into another. 
The question as to where the line should be dra^m between 
the good, medium, and very bad milk or cream, must depend 



80 BUTTER-MAKING. 

upon the judgment of the receiver, and in a great measure 
upon the local conditions. Some of the creameries have no 
facilities for handling different grades of milk, and some sell 
butter on a market where no sharp distinction is made between 
good and poor butter. Others have, through experience, sat- 
isfied themselves that under American creamery conditions 
it does not pay to make too many grades, nor does it pay to 
grade too closely. Two, or at the most three, grades of but- 
ter can at times be manufactured in one creamery profitably. 
It is advisable to reject sour and abnormal milk. If accepted, 
it should not be mixed with the remainder of the milk, as it 
might contaminate all of it; or, the sour milk might cause 
coagulation, and thereby clog up the separators. If a can of 
milk is sour, but otherwise clean, it is not necessarily unfit 
for the production of first-class butter. If retained until after 
the sweet milk has been skimmed, it may be run through 
the separator successfully. 

2. The Use of Acid Tests. — Some creameries, especially 
the larger central cream plants, are now grading the milk or 
cream according to the amount of acid it contains. For instance, 
cream or milk containing .2% acid or less is classed as first 
grade; that containing from .2 to .4% as second grade, and 
the cream containing more than .4% acid as third grade. 
Mann's and Farrington's acid tests can both be used, but a 
more rapid and convenient way is to use a solution prepared 
from Farrington's tablets. The solution is prepared by taking 
one tablet for each ounce of warm water and allowing the 
tablets to dissolve. When one part of this alkaline solution 
and one part of milk are put together in a cup and mixed 
and the solution still retains a pink color, it shows that there 
is less than .1% acid in the sample tested. If two parts of 
alkali and one part of milk are mixed and the mixture remains 
pink, then there is less than .2% of acid. If the mixture turns 
colorless, it shows there is more than .2% acid in the sample. 
If three measures of alkali to one measure of milk are taken, 
and the mixture remains pink, that indicates that there is 



RECEIVING, SAMPLING, AND GRADING. 81 

less than .3% of acid, etc. By means of such a test the acidity 
can quickly be determined. 

The sample cups should be numbered to correspond with 
the number of each patron. The results of the tests should 
be noticed at once, as the action of the atmosphere affects 
the color. 

The acid tests are of value in grading cream, as a sour 
sample of milk or cream is either old or has been improperly 
kept and handled. The number of grades of cream and milk 
and the maximum limit of acid each grade can contain, are 
factors which must be decided according to local conditions, 
by the operator. 

3. Use of the Fermentation Tests. — Curdled, ropy, red and 
blue milk can, as a rule, readily be detected without the appli- 
cation of a special test, but there are cases when a person's 
senses are not sufficiently acute to detect samples of milk 
containing undesirable fermentations. Several instances have 
recently come within the authors' notice. A neighboring 
creamery was infested with a peculiar fermentation that 
caused a very rank flavor in the butter. The milk that came 
to the creamery was carefully examined, but without locating 
the source of the trouble. The cause could not be ascertained 
without the use of the fermentation test. 

It is in such instances that a fermentation test is of special 
value. As a rule, at least when the trouble first begins, it is 
milk from one particular patron that causes the trouble. This 
milk may appear to be normal, and yet contain germs which 
are very undesirable for the manufacture of the best quality 
of butter. 

Fermentation Te ts. — There are two tests which may be 
of general use; namely, the " Wisconsin Curd Test " and 
the " Gerber Fermentation Test.'' The former is used in 
cheese factories, but the latter is to be recommended in testing 
milk for butter-making. 

Gerber Test. — This test consists of properly made glass 
tubes which fit into a rack. This rack, containing the bottles^, 



82 BUTTER-MAKING. 

fits into a small round tin tank, which is kept about two-thirds 
full of water. The temperature of this water can be con- 
trolled by means of a lamp kept burning underneath, or by 
the use of steam. The milk from the different patrons is 
put into the glass tubes, and these tubes numbered so as to 
indicate to which patron each belongs. The temperature 
should be kept at about 104 to 106° F. for about six hours. 
Then the tubes are taken out, the milk shaken, and the appear- 
ance, smell, and taste of the milk noted. The tubes are warmed 
again for about another six hours, when they are again examined. 
If any samples contain a preponderance of abnormal ferments, 
the fact will usually appear in less than eighteen hours. If 
milk does not coagulate in twelve hours, or become abnormal 
in some way, it is supposed to be good. 

The special apparatus mentioned above is not absolutely 
essential, nor is the temperature employed considered by the 
authors to be the most suitable to give reliable results. Ordi- 
nary sample jars can be used, instead of specially prepared tubes. 
After the milk has been placed in the jars they can be kept 
in any convenient place, at a temperature of about 98° F. 
The best place to keep them is in a vessel containing water, 
the temperature of which can be controlled. 

Wisconsin Curd Test. — This test consists of taking some 
milk in a jar and adding about ten drops of rennet, which 
coagulates the milk. The sample is allowed to stand until 
the curd hardens, then it is cut into small pieces with a case 
knife; the whey is drawn off, and the curd allowed to stand 
at a temperature of 98° F. If there are any undesirable forms 
of bacteria present, they will reveal themselves by developing 
small holes in the curd, usually accompanied by a bad odor. 

This test is a very ingenious one for cheese-making. In 
butter-making the Gerber Fermentation Test, or a similar one, 
is more convenient. 

4. Grading Milk by Heating.— This test is not used very 
much in creameries; but in cheese factories the heating of 
milk in order to ascertain its suitability for cheese-making is 



RECEIVING, SAMPLING, AND GRADING. 



83 



practised to a considerable extent. This test is in common 
use in Canada. It consists of heating a small sample of the 
milk to be tested to 120° F. If it will stand this temperature 
without coagulating, it is considered to be good milk. If it 




Fig. 25, — Troemner's Babcock cream-testing scales. 





Fig. 26. — Tortion cream test- 
ing sca'es. 



Fig. 27. — Troemner's Bal> 
cock cream-testing scales. 



coagulates when heated to this temperature, it is too sour 
to be used for cheese. 

This heating may be considered an acid test. When milk 
contains about .3% acid, it usually coagulates when heated. 
It should be borne in mind in this connection that different 
samples of milk do not coagulate when containing exactly the 
same amount of acid, and at the same temperature. Some 
samples will coagulate upon heating when containing little 



84 



BUTTER-MAKING. 



less than .3% acid, while others will not coagulate until more 
than .3% acid has developed. 

In practice the temperature (120° F.) is not always considered, 
A small portion of the sample to be tested is put into a tin cup. 
The cup containing the milk is put into hot water or over a jet 
of steam. When hot its characteristics are noticed. 

5. Use of Babcock Test and Lactometer. — These tests are 
of special value in detecting watered or skimmed milk. When- 






FiG. 28. — Acid carboy trunnion. FiG. 29. — Acid hydrometer. 

ever a sample of milk appears watery or blue, it is fair to presume 
that water has been added. The test for specific gravity and 
the test for fat can then be applied to such samples of milk. 
As a rule composite samples are taken daily at creameries, and 
the patrons paid according to the fat delivered. For this 
reason water adulteration is not very common at creameries, 
but is practiced to a greater extent in the milk-suppHes of 
cities. The use of the lactometer in connection with the Bab- 
cock test has already been referred to under the heading of 
''Specific Gravity of Milk." 



RECEIVING, SAMPLING, AND GRADING. 



85 



There are two tests commonly used for determining fat in 
milk, viz., the Babcock and Oil-test Churn. The latter method 
is rapidly giving way to the former. The Babcock test is un- 
doubtedly superior, though many still prefer the Oil-test. 





Fig. 30.— 17.6 c.c. 
pipette. 



milk 



Fig. 31. — Automatic 
17.6 c.c. pipette. 



Fig. 32.^— Automatic 
Russian pipette. 



The Babcock method of testing consists of taking 18 grams of 
the substance to be tested into a special graduated bottle as 
shown in illustration. Milk is measured out with a pipette hold- 
ing 17.6 c.c. Cream, butter, and cheese, or any other substance 
which cannot be measured accurately, should be weighed. 
The measured quantity of milk in the bottle is then digested by 
adding 17.5 c.c. of commercial sulphuric acid having a specific 
gravity of about 1.82. The acid digests all proteids and sets 



86 



BUTTER-MAKING. 



free the fat. The contents of the bottle should be well shaken 
at once after the acid has been added. 

The bottle with its contents is then whirled about five 
minutes in a centrifugal machine at a rate depending upon the 
diameter of the machine, usually about 850 to 1000 revolutions 





Fig. 33. 


Fig. 34. 


Fig. 35. 


Fig. 36. 


Fig. 37. 


Skim-milk 


Whole-milk 


Cream test- 


9-gram cream 


Cream 


test-bottle. 


test-bottle. 


bottle 


test-bottle. 


test-bottle 



Babcock Test-bottles. 



per minute. The machine is then stopped and filled to the 
neck of the bottle with pure hot water. Distilled water is 
preferred. The bottles are then whirled two minutes, and 
hot water added again until the fat rises in the neck where it 
can be read. The bottles are then whirled again for about one 
minute. The machine is then stopped and the fat read in 
percentage direct from the bottle. By using a pair of dividers 



RECEIVING, SAMPLING, AND GRADING. 



87 



the reading may be facilitated. The temperature at the time of 
reading should be between 120° and 140° F. 

There are three very common defects in the clearness of fat 
reading: (1) The fat contains black, charred, fiocculent matter 
at the bottom of the fat column. This is commonly caused by 





Fig. 38. _ Fig. 39. _ 

Wagner's skim- Ohlson's skim- 
milk bottle. milk bottle. 
(Both with pneumatic fat- 
indicator (pat.).) 



Fig. 40. Fig. 41. 

Butter test-bottle, and Russian Babcock 

funnel which holds test-bottle and 

about 9 grams of reading-tube, 
butter. 



using too much or too strong acid or mixing milk and acid at too 
high a temperature. The remedy is to use less acid or to 
cool milk and acid before mixing. The black charred matter 
may also be due to allowing the acid to stand in contact with 
the milk too long a time before mixing or by pouring acid 
through the center of the milk. (2) There may be a layer of 
white fiocculent matter at the bottom of the fat column. This 
is due to not having used enough acid or to the temperattire of 
milk and acid being too low or to not mixing the acid and milk 



88 



BUTTER-MAKING. 




Acid measure. 





Fig. 42.— Acid dipper. Fig. 43.— Combined acid bottle. 





Fig. 44. —Automatic acid pipette. Fig. 45. — Wagner's acid siphon. 



RECEIVING SAMPLING, AND GRADING. 



89 



thoroughly. The remedy is to use more acid, or to warm milk 
and acid before mixing, or to shake the mixture thoroughly 
before whirhng. (3) Occasionally there is a layer of impure 
foam at the top of the fat column. This is generally due 




Fig. 46. — The oil-test churn. 



to the use of hard and impure water. The remedy is to use 
pure distilled hot water. For more detailed information on 
this subject see "Testing Milk and its Products," by Farrington 
and WoU. 

Necessity of Good Milk. — All authorities agree that the best 
grade of butter and cheese cannot be made from sour or tainted 
milk. The two countries renowned for the excellence of their 



90 



BUTTER-MAKING. 



dairy products — Denmark and Canada — owe their success 
largely to the purity of the milk furnished by their patrons. 
Makers who have won for themselves national reputation in 
cheese- and butter-making have almost invariably been men 
who insisted on getting first-class milk. Badly tainted milk 




Fig. 47. — Wizard tester. 



should not be manufactured into food. The method of classify- 
ing milk and cream and paying for each according to quahty 
has been adopted by some creameries, especially by some of 
the large central plants. The object of this is to induce those 
patrons who are sending poor milk or cream to furnish a better 
grade. It seems more practical with milk than with cream, 
because the average maker dislikes to reject a can of cream. 



RECEIVING, SAMPLING, AND GRADING. 



91 



owing to the loss the patrons would sustain. If such cream is 
received, it should be churned separately, and the butter marked 
and sold on its merits. The practice of taking in poor milk 
and cream should be discouraged. One of the authors has 
come in contact with many patrons in different parts of the 





Fig. 48. — Speed indicator. Fig. 49.— Twentieth-century hand tester. 




Fig. 50. — Russian Babcock tester. 

country and has yet to find the first patron who seriously 
objected to taking his milk Imck home when he was thoroughly 
convinced that it was not in good condition. Patrons as a 
rule respect the maker who keeps his creamery in a good sanitary 
condition and insists on getting good milk. It should be the 
aim of every creameryman to make the highest grade of butter 
possible. 



92 



BUTTER-MAKING. 




Fig. 51. — Babcock test traveling outfit. 




Fig. 52. — The Agos steam tester. 



RECEIVING, STAMPING, AND GRADING. 93 

Sampling of Milk.^The sampling of milk and cream for 
fat tests is one of the most delicate problems with which the 
creamery operator has to deal. If a proper sample is not 
obtained, the ultimate test will not be correct, no matter how 
carefuhy the succeeding steps may be carried out. There are 
two methods of sampling in use: First, samphng with a small 
dipper, and second, samphng with a sample-tube, or milk- 



FiG. 53. — Danish milk-wagon. (N. Y. Produce Review.) 

thief. The sampling of milk for composite samples should be 
done every day, and the samples taken should represent the 
average quality and form a certain proportionate part of the 
milk or cream delivered. 

In order to get a sample which represents the average quality, 
the milk or cream delivered must be thoroughly stirred, so as 
to get an even distribution of the fat. 

In order to get a proportionate part of the milk or cream 
dehvered from day to day, it is necessary to use a sampling- 
tube. 

The sampling of milk or cream with a dipper for composite 
samples has been in use so long that this method has become 



94 BUTTER-MAKING. 

very general. If composite samples are not kept, and the 
testing of each patron's milk is done every day, the dipper 
method of sampling answers the purpose. If thick cream is 
being delivered, the dipper may be found to work better than 
the sampling-tube, as the cream in some cases may be so viscous 
that it will adhere to the sides and ends of the tube, and in 
that way prevent the cream from entering. The sampling- 
tube may also retain some of the thick cream on the inside 
and if not rinsed out properly each time, the adhering cream 




Fig. 54. — Delivering milk in Santiago. (Creamery Journal.) 

is likely to interfere with getting a fair sample of the succeeding 
lot. If the sampling-tube is rinsed in hot water each time, this 
probable mistake will be obviated. 

Sampling- tube. — At creameries where milk is received, 
the sampling-tube, or milk-thief, gives the best results and 
satisfaction. It is very difficult in practice to get a propor- 
tionate sample with a dipper, from day to day. To illustrate: 
A patron who delivers 200 pounds of milk testing 3% fat one 
day may on another day deliver 100 pounds of milk testing 
5% fat. If a dipperful is taken from each for a composite 



RECEIVING, SAMPLING, AND GRADING. 95 

sample, the test of that composite sample will be 3 + 5-^2, 
or 4%. According to this test, these 300 pounds of milk 
delivered will contain 12 pounds of butter-fat. In reality 
6 pounds of fat were delivered in the 200 pounds, and 5 pounds 
of fat in the 100 pounds, making a total of 11 pounds of fat. 
Thus we see that the dipper method is not rehable, and in this 




Fig. 55. — The McKay cream and 
milk sampler. 



Fig. 56. — Cream sampling-tube. 



case the patron was paid for 1 pound of butter-fat too much 
for the two days' delivery. If the sample taken from the 
200 pounds of milk had been twice as great as that taken from 
the 100 pounds of milk, then the composite test would have 
been perfect, no matter whether it had been taken with a 
dipper or with a sampling- tube. If the same weighing-can 
is used every day, then an exact proportion for a sample can be 



96 BUTTER-MARING. 

maintained, if the sampling-tube is put down perpendicularly 
into the milk every day at the same place in the weighing-can 
and otherwise carefully taken. 

In case the cream is being collected from different patrons 
by a hauler, a milk-thief often works unsatisfactorily. This 
is especially true during cold weather. A cream tube similar 
to the one shown in the accompanying illustration is more 
effective. The way in which the tube is used is apparent from 
the figure. If a certain patron has 40 pounds of cream, the 
cream is filled to the 40 mark on the scale of the tube. If he 
has 30 pounds, it is filled to the 30 mark, etc. 

Sampling Churned Milk. — It occasionally happens that the 
milk arrives at the creamery slightly churned. This is espe- 
cially the case during the summer. Usually such milk is 
sampled in this condition, but if it is desired to find the per- 
centage of fat in such milk in its unchurned condition, it is 
essential to melt the churned fat before sampling. If the 
butter has been churned into a few large lumps, these lumps 
can be taken out in a pan, or pail, with a comparatively small 
amount of milk, and this heated until the butter has melted. 
Then this is remixed with the milk from which it was first 
taken, and sampled while it is being stirred. 

The churning of the milk during transit is mainly due to 
two things: First, to a high temperature of the milk (65° to 
85° F.), and secondly, to hauling partly filled cans a long distance 
over rough roads. If the temperature of the milk is low (about 
50° F.), when it leaves the producer, then there is seldom any 
danger of having churned milk at the creamery. 

Frozen Milk. — When milk is cooled to 31° F., or below, the 
milk freezes. Ice forms near the sides and bottom of the can, 
until a funnel-shaped cavity filled with milk is left in the center. 
According to both Richmond and Fleischmann, the icy por- 
tion contains more water than the unfrozen milk, and the 
unfrozen portion is rich in solids. According to Farrington, 
when 25% of the sample of milk was frozen, the icy portion 
contained about 1% less fat than the original portion. ^Vlien 



RECEIVING, SAMPLING, AND GRADING. 97 

about half of it was frozen there was no great difference in 
the fat -content of the frozen and unfrozen parts. 

In practice, however, it seems to be different. When a 
can full of partly frozen milk is sampled at the creamery, the 
unfrozen milk nearly always contains less fat than the original 
sample. This can be accounted for by opening the can of 
milk and noting the amount of frozen cream on the sides near 
the top. Whether the unfrozen portion contains less or more 
fat than the original depends, therefore, upon conditions. At 
any rate, frozen milk has a composition different from that 
of the original sample. On this account an accurate sample 
cannot be had, unless the frozen portion be first completely 
melted and well mixed with the remainder. 

Sour and Coagulated Milk. — In order to get a fair sample 
from a can of sour and coagulated milk, it must be stirred 
very thoroughly, so as to bring the coagulated milk into a 
uniform emulsion. A better sample can usually be obtained with 
a dipper. If the milk is not too thick, a fair sample can be 
obtained by the use of the sampling-tube. In order to reduce 
a can of coagulated milk to a thoroughly uniform quality, it 
is best to pour it from one can into another. This mixes it 
much more completely than if the sample were simply stirred 
with a dipper or any other kind of an agitator. 

Apportioning Skimmed Milk. — The amount of skimmed 
milk to be received by the patron depends largely upon the 
thickness of cream skimmed, and upon the amount of skimmed 
milk retained at the creamery for various purposes. The 
amount of skimmed milk generally returned by creameries 
varies between SO and 90% of the whole milk delivered. 

Most up-to-date creameries now make use of skimmed - 
milk weighers. Where such are employed the man, who receives 
the milk, hands each patron a check for the amount of milk 
delivered. This check is put into the skimmed-milk weigher, 
and it allows an amount of skim-milk to flow out, corre- 
sponding to the number of pounds indicated on the check. 

In case a skimmed-milk weigher is not employed, it is 



98 



BUTTER-MAKING. 



essential to have a man at the skim-milk tank to weigh 
out the proper amount of skimmed milk to each patron. If 




Fig. 57. — Check-rack. 



the patrons are allowed to weigh out their own skimmed milk, 
mistakes are frequently made, which result in more or less 
dissatisfaction. It is cjuite customary for butter-makers to 




Fig. 58. — The Ideal skim-milk weigher. 

draw a chalk line on the outside of the can some distance 
below the surface of the milk. This indicates the point to 
which the can may be filled with skimmed milk. 



CHAPTER VIII. 

COMPOSITE SAMPLES. 

Definition. — In order to avoid testing each patron's milk 
or cream every day for fat, a small sample, which represents 
the average quality and a proportionate part of the whole, is 
taken from each patron's milk every day and placed in a jar. 
A preservative of some kind is previously added, which keeps 
it from spoiling. This is called a composite sample. 

When to Sample. — Some makers prefer to sample the milk 
or cream delivered every day; others prefer to sample every 
other day. Some creamery operators, again, sample four or 
five times in succession at intervals, the patrons being unaware 
of the time when the sampling is to take place. The most 
reliable and practical method, however, is to take a sample 
every day, and test it for fat at the end of every two weeks. 
When cream is received it is not reliable to take composite 
samples. 

Kind of Preservative to Add. — A number of different pre- 
servatives are now in use, and different ones are being recom- 
mended for creameries and cheese factories by various authori- 
ties. Even a few of the best authorities differ as to which 
one of the preservatives gives the best results. 

Among the most common of the milk preservatives, and 
less poisonous than certain others, are salicylic acid, borax, 
boracic acid, and bicarbonate of soda. Among the more vio- 
lent poisons and strong preservatives are formaldehyde and 
its compounds, chloroform, corrosive sublimate, and bichromate 
of potash. Bichromate of potash and corrosive sublimate are 
the two most commonly used in preserving composite samples. 
The former is recommended highly by Farrington & Woll on 

99 



100 



BUTTER-MAKING. 



account of its relative harmlessness, its cheapness, and efficiency. 
While bichromate of potash is relatively efficient in its 
preservative effect, and not so poisonous as some of the others, 
it does not give as general satisfaction as does corrosive sub- 
limate (mercuric chloride), unless relatively greater precau- 
tions are taken. If the composite samples preserved with 
bichromate of potash are left standing in the light very long, 
a leathery scum forms on the top, which is very difficult to 
dissolve in the sulphuric acid. This is claimed to be due to 
the reducing influence of light on chromate solutions. If too 





Fig. 59. — Composite 
sample bottle. 



Fig. 60 — Composite samples and rack 
to hold sample jars. 



much bichromate of potash is added, the sulphuric acid added 
digests the curd with difficulty. When the sulphuric acid is 
added the curd is precipitated into a heavy, gray-colored coag- 
ulum, which dissolves with difficulty in the acid. 

According to the authors' experience, corrosive sublimate 
tablets can be highly recommended. The tablets contain a 
color, which, when dissolved, colors milk, so that it can readily 
be distinguished as not being fit for human food. The tab- 
lets are very poisonous, but are more efficient in their preser- 
vative effect than bichromate of potash. They can be obtained 
from any creamery-supply house. 

During the winter, when the samples are kept comparatively 
cold, less preservative is needed than in the summer. One 




o 



o 



102 BUTTER-MAKING. 

corrosive sublimate tablet will keep a half-pint to a pint of 
milk or cream in good condition for about two weeks in summer, 
and about three weeks in winter, providing the sample is properly- 
cared for. Some makers are practicing testing at the end of 
every month during the winter, and every two weeks during 
the summer. Testing at the end of every month saves labor,, 
but it is not a reliable method to follow under all conditions, 
as some of the samples are likely to be somewhat impaired 
after standing so long. 

Arrangement of Composite Samples. — Pint glass jars with 
covers are, so far as known, the most convenient vessels tO' 
use for composite samples. Shelves should be arranged in the 
weighing-room on which to keep the bottles. If possible, it 
is best to have them in a case closed with glass sliding doors. 
This is neat, and, if the glass doors fit well, the samples are in 
some measure protected in case of quick, unexpected changes 
in temperature. These sliding doors should be locked when 
the creamery operator is absent from the creamery, in order 
to prevent any tampering with the composite samples. 

The best method of arranging the sample jars is to have all 
the jars belonging to the patrons of each route standing in 
one group, or on one shelf together, if possible. The bottles 
are numbered to correspond with the number given each patron 
on the milk sheet. The name of the hauler, or the number 
of the route, can be put on each shelf. The samples be- 
longing to those who haul their own milk can be put on another 
shelf. These can be designated as individual haulers. Such a 
classification, when the bottles are plainly numbered, will often 
prevent the mistakes that are likely to occur if the bottles are 
simply numbered and put into a rack together. 

Care of Composite Samples. — In the first place the jars should 
be kept scrupulously clean. It makes the test unreUable if 
the jars are left covered with milk and molds round the neck 
from one month to another. When the samples have been 
tested the jars should be thoroughly cleaned, and, if necessary, 
scalded, before they are used again. Care should be taken to 



COMPOSITE SAMPLES 



103 



spill as little milk as possible around the neck, inside as well 
as outside, of the bottle when the sample is put in. If the 
milk is spilled there, it makes an unattractive appearance. 
Very often it becomes moldy, and, as more milk is added and 
the sample shaken every day, this mold gradually extends 
down the sides of the bottle. This causes the composite sample 
to be infested with undesirable growth, and to spoil sooner than 




Fig. 62. — Testing-room in ^Model Dairy, St. Louis Exposition. 
(Chicago Dairy Produce.) 

it would if greater care were taken in keeping the milk from 
coming in contact with the sides of the bottle, before coming 
in contact with the preservative. 

It is important also that the sample jars be well covered, 
otherwise the moisture evaporates and causes the milk or cream 
to dry up. It also makes the test unreliable by increasing the 
per cent of butter-fat. A gentle rotary motion should be 
given each jar when a sample is added to it to mix the cream, 
w^hich rises to some extent after the milk has stood a while. 



104 BUTTER-MAKING. 

Average Sample. — It is sometimes desirable to obtain an 
average test of the milk from a whole day's delivery. Tliis 
can be obtained in two ways : First, by taking a sample from 
each patron's milk with a sampling-tube, and putting it all 
together in one jar. The result represents an average test, pro- 
viding the samples have been correctly taken. Second, an aver- 
age test can be had by boring a small hole in the conductor-head. 
When the milk passes over this hole, a small portion of it 
drops through. A vessel of some kind can be put underneath 
to catch the drops. Such a drip-sample will represent very 
accurately the average quality of the milk received at the 
creamery. If it is desirable to keep this sample, a preservative 
can be added to it. 

Composite Sampling without the Use of Preservatives. — 
Pipettes can be obtained holding 5.87 c.c. of milk. These are 
one-third the size of the ordinary 17.6 c.c. pipette used for 
the Babcock test. With this small pipette a sample may be 
taken every day from each patron's milk, during three suc- 
cessive days, and emptied into the same test-bottle each 
day. At the end of three days the samples may be tested 
and the bottles cleaned, ready for use again. 

Accurate composite samples may be obtained in this way, 
providing the sample in the pipette is correctly taken each 
day. No preservative is needed. The preservatives are added 
to the composite samples to prevent curdling. The test-bottles 
may be placed on a shelf, or preferably in a rack made to hold 
them. They should be marked in such a way as to identify 
them. A good way is to mark them the same as the com- 
posite jars, the number on the jar corresponding to the number 
on the milk-sheet for each patron. 



CHAPTER IX. 

CREAMERY CALCULATION. 

Find the Average Per Cent of Fat. — In calculating the 
average per cent of fat from a niunber of cows, or the milk 
furnished by the different patrons, the mistake of adding the 
tests of aU the samples together and dividing the sum by the 
total number of samples tested is often made. Milk from 
different patrons, or from different cows, will always vary, 
some in quality and some in quantity, and in order to get a 
correct average test, both quantity and quahty must be taken 
into consideration. The wrong way of calculating the average 
percentage may be illustrated as follows : 

Sample. Milk Delivered. Per cent Fat. 

1 50 lbs. 5.0 

2 100 " 4.5 

3 500 " 3.0 

4 300 " 3.5 

4)16% 
4 

The average test, according to the wrong method, =4%. 
The correct way of calculating the average percentage may 
be illustrated as follows : 

Sample. 
1 
2 
3 
4 



105 



Milk Delivered. 


Per cent Fat. 


50 lbs. 


5.0= 2.5 lbs. fat 


100 " 


4.5= 4.5 " " 


500 " 


3.0 = 15.0 " " 


300 " 


3.5 = 10.5 " " 


950 lbs. 


950)32 . 5 lbs. fat 




3.42 



106 



BUTTER-MAKIXG. 



The average test, according to the correct method, is 3.42%. 

It will be seen from the example quoted that there is a 
difference of more than .5%. If the percentage of fat or 
the number of pounds of milk is uniform, then it does not 
matter which of the two ways illustrated above is used. But 
as uniformity in either of these respects scarcely ever exists 
in practice, the only correct way of calculating the percentage 
is to hnd the total number of pounds of fat and divide it by 
the total number of pounds of milk; the result is .0342, which 
mav be written 3.42%. 















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Fig. Go. — A Russian co-ope^ati^•e creameiy Iti Siberia. 
(I'. S. Governinent Bulletin.) 

It is very connnon for creamery patrons to test the milk 
from each of their cows, then add the tests together and divide 
by the tinal number of cows tested. The result they will 
call the average test, and frequently such tests are made use 
of as evidence against a creamery operator to prove that his 
tests at the creamery were not correct. The fallacy is evident 
from what has been said above. 



CREAMERY CALCULATION. 107 

The same mistake is also likely to be made in finding 
the average test from several creamery-plants and skimming- 
stations. 

Calculation of Overrun. — The amount of overrun is the 
difference between the amount of pure butter-fat, and the 
amount of butter manufactured from that given amount of 
fat. This difference, divided by the amount of fat and multi- 
phed by 100 will give the percentage of overrun. The calcu- 
lation of the overrun in the creamery should always be made 




Fig. 64. — A Cheshire creamery, England. (London Creamery Journal.) 

from the fat-basis on which the patrons are being paid. If 
the fat is dehvered in the cream, the overrun should be calcu- 
lated from the fat in the cream. The overrun calculated from 
the composition of the butter manufactured would not be an 
indication of the correct overrun, as there might be serious 
losses of fat sustained during the different steps in the manu- 
facture, such as from inefficient skimming, incomplete churning, 
and general losses in the creamery. It is possible that butter 
might show a high content of the substances not fat, and 
yet not show a good overrun on account of losses; while butter 
containing only a medium high moisture-content might show 
as great or greater overrun on account of thorough and efficient 
work during the different steps of manufacture. 



108 BUTTER-MAKING. 

The amount of overrun depends upon: 

1. Thoroughness of skimming. 

2. Completeness of churning. 

3. General losses in the creamery. 

4. Composition of the butter manufactured. 

The theoretical overrun, however, may be quite accurately 
calculated from the composition of the butter manufactured 
in a well regulated creamery. In creameries where the con- 
ditions of separation and churning are almost perfect, the 
amount of fat lost in the buttermilk and the skimmed milk 
is quite constant from day to day, and should not exceed .1% 
in the skimmed milk and .2% in the buttermilk, according 
to the Babcock test. Basing the calculations upon the above 
figures, the theoretical overrun may be calculated from the 
composition of the butter as follows: 

If, for instance, we start with 1000 pounds of milk-testing 
4% fat, there will be a total of 40 pounds of fat. If we skim 
32% cream from 4% milk, we should have -^^, or |, of it cream, 
and the remainder skim-milk, or 125 pounds of cream and 
875 pounds of skimmed milk. If there were .1% of fat in the 
skinmied milk, there would be a loss of .875 pounds of fat during 
skimming. There would then be 39.125 pounds of fat in the 
125 pounds of cream (40 -.875 = 39. 125). If 10% of starter 
were added to the cream we should get 137.5 pounds of cream 
testing 28.4%,. (125 pounds cream X 1.10= 137.5 pounds cream; 
39.125 -^137. 5 = 28.4% fat.) By churning this cream we 
should obtain about 100 pounds of buttermilk. If it tested 
.2% fat there would be a loss of about .2 pounds of fat, making 
a total loss of fat in skim-milk and buttermilk of 1.075 pounds. 
Subtracting this total loss of 1.075 from 40 pounds we would 
have 38.925 pounds of fat left to be made into butter 
(40-1.075 = 38.925 pounds of fat). If the butter on analysis 
proves to contain 82% fat, the total number of pounds manu- 
factured will be 38.925-^82 = 47.47 pounds of butter. 47.47- 
40 = 7.47 pounds theoretical overrun, and 7.47 -^40 X 100= 18.7% 
overrun (theoretical). 



CREAMERY CALCULATION. 109 

It is evident that the losses of fat will vary according to 
the different conditions. The richer the cream, and the less 
fat in the whole milk to be skimmed, the more skim-milk there 
will be; the thinner the cream, and the more fat there is in 
the milk to be skimmed, the less skimmed milk there will be, 
and consequently with the same skimming efficiency less fat 
will be lost in the skim-milk. The thinner the cream is the 
more buttermilk there will be. These conditions must be left 
for the operator to govern according to the conditions present. 

The actual amount and per cent of overrun as determined 
in creameries is calculated as described previously. The 
formula is as follows: 

Butter-fat ^^^ . r . i 
7— X 100 = per cent 01 actual overrun. 

Calculation of Chum-yield. — Instead of expressing the in- 
crease of butter over that of fat in the percentage overrun, 
as above, it is often customary among creamerymen to speak 
of the ''churn-yield." For instance, they say that their test 
was 3.90, and their churn-yield was 5, meaning that on the 
average each 100 pounds of milk contained 3.9 pounds of 
fat and yielded 5 pounds of butter. The churn-yield is always 
expressed in percentage, and is obtained by dividing the total 
pounds of butter obtained by the total pounds of milk from 
which the butter was made, according to the following formula: 

Pounds of butter , ^^ , ... 

-p; ] — ^ — rpj— X 100 = churn-yield. 

roimds 01 milk 

In case cream is handled instead of milk, the same may 
be obtained by substituting "pounds of cream" for "pounds 
of milk" in the formula. 

Calculation of Dividends. — The method of calculating 
dividends will vary according to the agreements between the 
manufacturer of the butter and the milk and cream producers. 



110 



B U TTER-MA KING. 



Some manufacturers agree to make the butter for so many 
cents per pound of butter (usually 3 or 4 cents). Occasionally 
the creamery proprietor agrees to pay a final fixed sum for milk 
delivered containing a definite amount of fat (usually 4%). 
These two methods are not in use much at the present time, 
.although in the eastern part of the United States the method 
<of paying the operator so much per pound of butter-fat manu- 
factured is quite common. 




Fig. 65. — Jeinsen creamery, Barnten Pro\'ince, Hamburg, Germany. 
(Creamery Journal.) 



The two methods most commonly used, especially in the 
central West, are as follows: 

(1) Pay so much per pound of butter-fat based upon some 
standard market price, such as Elgin or New York. The 
amount paid now by the central plants for butter-fat is usually 
2 or 3 cents per pound below "New York Extras," and the 
company pays all freight or express charges. 

(2) Pay per pound of fat based upon the net income of the 
creamery. 



CREAMERY CALCULATIOX. Ill 

1. The former method of paying for butter-fat has become 
quite common. Nearly all the hand-separator or central plants 
are paj'ing for butter according to this method. Payments are 
usually made everj^ two weeks. Although this causes more 
work, it LS much more satisfactorj'- to the patrons than to pay 
only at the end of each month. 

In order to calculate dividends when paid at the end of 
two weeks or at the end of each month, the first step is to 
find how many pounds of butter-fat have been delivered by 
each patron. If compo.site samples are taken, and these 
tested for fat at intervals of one week, which would make about 
four tests during the month, and two during half a month, 
the results of the several tests may be added, and the sum 
di\ided by the number of samples tested. This may give the 
average test, but it must be borne in mind that this method 
is also likely to give "WTong results. Especially is this so 
when cream Is delivered which varies in quantity as well a.s 
quality during the different parts of the month. 

If cream only is being received, it ls a good plan to test 
each patron's cream every day, as it Ls more or less difficult 
to get absolutely accurate composite samples from creams of 
different richness. Besides this, the patrons can get the test 
as weU as the weight of the cream of each pre^dous days de- 
liver}^, and thus know how their accoimt stands from day to 
day. A httle more labor Ls involved in doing this, but in the 
long run it keeps the patrons better satisfied. 

2. If the price of butter-fat per pound is being based upon 
the net income, as is the case in nearly all co-operative cream- 
eries, and also in many proprietary' creameries, the first step 
is to find out how much butter-fat each patron delivered during 
the specified time, — two weeks or a month, whichever may 
be the case. "When this has been obtained, the total pounds 
of fat dehvered by aU the patrons are foimd. From the gross 
income the total expenses of running the creamer}^ are sub- 
tracted. The remainder represents the net income. This is 
then di\-ided by the total pounds of fat delivered to the cream- 







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CREAMERY CALCULATION. 113 

ery, and the quotient represents the price per pound of butter- 
fat to the patrons. 

Knowing the price of one pound of fat to be paid to the 
patrons, the sum due to each patron is found by multiplying 
the price per pound by the total number of pounds of fat each 
patron delivered during the specified time. 

In some instances provisions are made for a "sinking fund." 
This is a name given to a fund raised by deducting so much 
per pound of fat, or per 100 pounds of milk, from each patron's 
delivery at the end of each month. This fund is for the pur- 
pose of paying off a debt gradually, or for raising a fund for 
new equipment, or other improvements in the creamery. In 
case such money is to be withheld, it is deducted previous to 
making the final calculation. 

Cream-raising Coefficient. — By the term cream-raising coeffi- 
cient we understand the percentage of fat removed from the 
milk during the process of separation. The calculation of the 
cream-raising coefficient may be illustrated as follows: 

Suppose we have 100 pounds of milk containing 4% fat, 
and yielding 85 pounds of skim-milk and 15 pounds of cream, 
the skim-milk containing .2% fat. 

Total fat in whole milk = 100 lbs. X4% =4 lbs. 
Total fat in skim-milk = 85 lbs. X.2% = .17 lbs. 
Total fat in cream = 4 lbs. -.17 lbs. =3.83 lbs. 

■^ — -T =95.75% of the total 4 pounds of fat, or the 

cream-raising coefficient. 

Statement to Patrons. — A complete statement should be 
made each time a settlement is made, and accompanied with 
the check. A statement similar to the following one may 
serve as an example : * 



* Creamery Butter-making, by Michels. 



114 



BUTTER-MAKING. 
CREAMERY COMPANY 



IN ACCOUNT WITH 



Mr. 



For the month of 



190. 



Cr. 



No. pounds milk dehvered 

by you 

Average test .... 
No. pounds butter-fat . 
Price per pound . . S 



Dr. 



Pounds butter at . . 

Cans, at 

Cash 

Hauling at . . . per 100 lbs 



Balance due you 

Total pounds milk delivered at creamery 
Average test at creamery .... 
Total pounds butter-fat at creamery . 

lbs. at 



Sales of butter 



l—- 



Less 



cts. for making. 



Balance due patrons . 
Per cent overrun . 
Testing witnessed by 



_Prest. 

_Secy. 



At the end of the year a final statement should be made 
by the respective officers, similar to the following one: 



ANNUAL REPORT. 

Incorporated 190 .. . Commenced Operations, 190 . 

Annual Report, 190. . . 

of the 
CREAMERY COMPANY 

of , , Iowa. 

( 



_Butter-maker;_ 



_Asst. Butter-maker) 



Capital Stock 



Paid in 



OFFICERS AND DIRECTORS. 

President, : — Secretary, 



-Treasurer. 



CREAMERY CALCULATION. 



115 



SECRETARY'S REPORT. 

To the Stockholders: Your Secretary herewith submits the following 
report for the year ending December 31, 190. .. 

Total pounds of milk received 

Total pounds butter-fat contained in same 

Total pounds butter manufactured 

Average test of butter-fat per hundred pounds of milk 
Average yield of butter per hundred pounds of milk. 
Average price paid per hundred pounds of milk . 
Average price paid per hundred pounds of butter-fat 
Average per cent increase of churn over test (overrun) 
Average price received per pound of butter 
Average monthly expenses of running creamery . 
Average cost of manufacturing butter per pound. 



Followir 

January 

February 

March 

April 

May . 

June . 

July 

August 

September 

October 

November 

December 

Totals 



is a Monthly Statement for the year 190 



STATEMENT OF CASH RECEIVED AND DISBURSED. 



Receipts. 
Received for butter 



Total amount of cash re- 
ceived and paid to 
Treasurer .... 

Cash balance in hands of 
Treasurer, Jan. 190. . 
Total .... 



Disbursements. 

Paid to patrons for milk 

Running expenses of cream- 
eiy and supplies on hand 

Paid for machinery, ma- 
terial, repairs, etc. (out 
of percentage fund) . 

Paid dividend on stock for 
190. . (out of percentage 
fund) _ 

Paid dividend on stock for 
190. . (out of percentage 
fund) 

Total amount of orders 
drawn on Treasurer . 

Cash balance in hands of 
Treasurer, Jan. 190. . 

Total .... 



116 BUTTER-MAKING. 

TREASURER'S REPORT. 

To the Stockholders of the Creamery Company: Your 

Treasurer herewith submits the following report: 

Statement of Cash Received and Disbursed. 
Receipts. Disbursements. 

Total Total 

Respectfully submitted, , Treasurer. 

, Cashier of Bank. 

REPORT OF AUDITING COMMITTEE. 

To the Stockholders of the Creamery Company: 

We, the undersigned, appointed by your Board of Directors to examine 
and audit the Books, Accounts, and Vouchers of the Secretary and Treas- 
urer of the Creamery Company for the year 190. . . , hereby 

certify that we have carefully examined the same and compared them with 
the above reports of said officers, and find them correct. 

In witness whereof we have hereunto set our hands at , Iowa, 

this .... day of a.d., 190. . .. 



Auditing Committee. 



Paying for Fat in Cream Compared with Paying for Fat in 
Milk. — It is evident that when patrons deUver fat in the form 
of milk the creamery operator sustains a loss in the skimmed 
milk, while if the fat is delivered in the form of cream, no 
fat is lost in the skim-milk at the creamery, and consequently 
the cream patron should receive more per pound of fat delivered 
than the whole-milk patron, providing the quality of the fat 
in the cream is as good as that in the form of milk. The butter- 
maker should obtain a larger overrun from the fat of the cream 
than he does from the fat of the milk. The amount which 
the patrons should be paid for fat, delivered in the form of 
cream, depends upon the thoroughness of skimming. If 
1000 pounds of milk testing 4% fat were bought and skimmed, 
there would be a loss of about .9 of a pound of fat during the 
skimming, which would make about 1 pound of butter, worth 
about 20 cents. If bought in the form of cream this loss would 
not be sustained. The above loss, during skimming, according 
to the figures mentioned, would amount to about half a cent 



CREAMERY CALCULATION. 117 

per pound of butter manufactured. The fat lost during the 
skimming process would amount to about 2% of the total 
fat. If the cream fat be increased by 2%, an approximate 
basis for paying milk and cream patrons is obtained. 

Degree of Justice in Paying Cream Patrons More per Pound 
of Fat than the Milk Patrons. — There is another side to this 
question of reaching an equity of payment between the cream 
patrons and milk patrons. A cream patron should not receive 
more pay than a milk patron, unless the quaUty of the fat 
is as good as that dehvered by the milk patron. It is a well- 
known fact that the fat dehvered in the form of cream is, as 
a rule, and has been, much inferior to that delivered in the 
form of whole milk. This is evidently due to the fact that 
cream is not delivered daily to the creamery, and that it is 
improperly handled on the farm, and during transportation. 
According to the results obtained in the Iowa Educational 
Contest, and other scorings, butter from hand-separator cream 
on an average seldom scores above 90, on a scale of 100. It is 
safe to come to the conclusion that there is at least a difference 
of three points in quality in favor of creamery butter made 
from milk-fat. Mr. Healy, one of the best known butter judges, 
claims that in the near future butter will be sold more accord- 
ing to quality than it is now. He asserts that a fair basis of 
paying for butter according to scores would be to deduct a 
quarter of a cent for every point that the butter scores below 91, 
and an addition of a quarter of a cent for every point it scores 
above. This would make a difference of three-quarters of a 
cent per pound in the selling price of butter made from whole 
milk and that made from hand-separator cream. It was 
figured above that the loss from skimming would amount to 
about half a cent per pound of butter, thus leaving a margin 
of one-quarter of a cent in favor of the whole-milk patron 
per pound of butter, rather than being in favor of the cream 
patron. 



CHAPTER X. 

HEATING MILK PREVIOUS TO SKIMMING. 

Reasons for Heating. — Owing to the fact that all separators 
will skim closer and not clog so easily when milk is heated, 
nearly all creameries heat or warm the milk previous to skim- 
ming. By thus heating and stirring the milk in a pure atmo- 
sphere, many undesirable odors or taints escape. With an 
increase of temperature, the viscosity of the milk is lessened, 
due chiefly to the softening and separation of the fat-globules. 
Such an increased fluidity of the milk lessens the resistant 
force of the fat-globules when exposed to the centrifugal force 
of the separator. The higher the temperature the more fluid 
the milk becomes, and consequently the easier the fat can be 
separated. 

By warming the milk to a high temperature and leaving 
it for some time, and then cooling quickly again to skimming 
temperature (90° F.) and separating, the skimming efficiency 
of the separator is increased materially. If the milk has been 
standing at a very low temperature for at least three hours, 
and then is quickly warmed up to the usual skimming tem- 
perature, and skinmied, the warming of the milk has com- 
paratively little effect in bringing it into a good condition for 
skimming. It will thus be seen that it is possible to skim 
milk at the same temperature, and yet get different results, 
due to previous temperature conditions. Duration of tem- 
perature should be considered as well as the temperature itself. 

The temperature to which milk should be heated previous 
to skimming varies according to different investigators. The 
temperature that has been mostly employed in the past in 

118 



HEATING MILK PREVIOUS TO SKIMMING. 119 

this country, and perhaps at the present time, is about 90° F. 
This comparatively low temperature was fixed owing to the 
supposedly bad effect high skimming temperature had upon 
the body of the finished butter. Exposing milk, at high tem- 
peratures, to the centrifugal force in a separator was said 
to producea greasy body in butter. According to some ex- 
periments conducted at the Iowa Experiment Station by the 
authors during the year 1902, milk can be skimmed at 175° F. 
without any injury to the quality of the butter, providing the 
cream is cooled to ripening temperature, or below, as soon 
as it has been skimmed. After the ripening has been com- 
pleted the cream should be exposed at least three hours to a 
low temperature (50° F.) previous to churning. 

If the milk is heated in any of the best modern heaters, 
no injurious results to the quality of the butter will be obtained. 
Prof. Dean, at the Ontario Agricultural College, has also found 
it practical to heat to pasteurization temperature previous to 
skimming. In many creameries in Denmark this method of 
heating milk is also followed. The Danes, as a rule, however, 
have the heated milk pass over a cooler before it goes into 
the separator. 

The chief difficulty encountered by the authors in heating 
milk to such a high temperature previous to skimming, was 
that the upper bearing in the separator got so hot that it was 
deemed injurious to the separator, although the bearing did 
not heat to such an extent as to cause the running of the 
machine to be abnormal in any way. 

Advantages of Warming Milk to High Heat Previous to 
Skimming. — The advantages of heating milk to a high tem- 
perature (175° F.) previous to skimming, may be summarized 
as follows: 

(1) Undesirable taints are eliminated from the milk to a 
greater extent than can be accomplished in any other way, 
without applying chemicals. 

(2) The heating of whole milk destroys the germs in the 
resultant skimmed milk and cream practically as efficiently 




o 



HEATING MILK PREVIOUS TO SKIMMIXG. 121 

as when heated after the skmiming process has been com- 
pleted. 

(3) Less heating and cooling apparatus is necessar3\ 

(4) Closer skimming. 

How Heated. — There are two methods by which milk is 
heated previous to skimming. First, by the use of direct 
live steam; second, by the use of heaters which heat with 
steam or hot water indhectlv. 



1') f^!^^ 




Fig. 68. — The Twentieth-century milk-heater. 

Heating of milk with direct live steam is accomplished in 
two wa}'s: first, by entering a steam hose into the vat full 
of milk; and, second, by making use of special heaters, which 
allow steam to come in direct contact with the milk as the 
milk passes through. 

The method of heating milk with direct live steam cannot 
be too strongly condemned, because it leaves bad effects upon 
the flavor of the butter. At the Milwaukee National Butter 
contest in 1903, where over eight hundred exhibitors were 
represented, the authors noticed that where the criticism 
"burnt, oily flavor" was made on the score card, the milk 
from which the butter was made had in most cases been heated 
with live steam. The burnt flavor may possibly be due to the 
sudden excessive heat to which the milk will be exposed when 
coming in contact with live steam. The greatest danger, 
however, in heating milk with live steam is, that impmities 
from the pipes and boiler are likel}^ to be transmitted to the 



122 BUTTER-MAKING. 

milk, and cause bad flavors. In most of the creameries the 
exhaust-steam from the engine is used to heat the water for the 
boiler. This steam is likely to carry with it cylinder-oil, which 
will impart undesirable flavors to the butter. Some creameries 
are also using boiler compounds for the removal of scales. 
These, when subjected to high heat and pressure, are likely 
to be transmitted to the steam-pipes, and from there with the 
steam into the milk. The scale and rust of steam-pipes are 
also likely to be transferred to the milk. 

The right way to heat milk previous to skimming is to make 
use of one of the special heaters on the market, which heat 
by the use of steam or hot water indirectly. 



CHAPTER XI. 

SEPARATION OF CREAM. 

In the process of the manufacture of butter it is essential 
that the fat of the milk shall be concentrated into a compara- 
tively small portion of the milk-serum. This concentration of 
fat carries with it a portion of all the other milk constituents, 
and the product is called cream. It is possible to churn milk 
without any separation, but a much greater loss is attendant, 
if the fat is not brought together by the process called separa- 
tion. 

The different kinds of cream may be classified according to 
the different methods of cream-separating: 

f Shallow-pan cream. 

(Gravity cream -{ Deep-setting cream. 
t Water dilution cream (hydraulic), 
p , •/. , r Hand-separator cream. 

^ ' ' \ Creamery-separator cream. 

Gravity Creaming. 

Shallow-pan System. — This method of creaming is used 
mostly on farms which are situated unfavorably in relation to a 
creamery, or for some other reasons do not send their milk to 
the creamery. It consists in placing the milk in shallow pans, 
from 2 to 4 inches in depth, as soon after milking as possible. 
The milk is then placed where it can be quickly cooled to a 
temperature of at least 60° F. A lower temperature than this 
is desirable if conditions permit. The atmosphere in the room 
in which the milk is standing must be pure, free from dust, 

123 



124 BUTTER-MAKING. 

draught, and any undesirable taints or odors, since it takes 
about thirty-six hours of quiet standing for the cream to rise. 
If there is a constant current of air in the room, a leathery 
cream is likely to form. At the end of this time the cream is 
removed by the use of a skimmer, made especially for this 
purpose. It is difficult, however, to remove all the cream by 
this means. 

If the conditions are such that cool water can be constantly 
circulated around the pans containing the milk, the tempera- 
ture can easily be made to go below 60° F., and the creaming 
process is facilitated. When such conditions are present, the 
depth of the milk in the pans can safely be increased to about 
6 inches. Under the most favorable conditions about .5% 
fat will remain in the skimmed milk. 

Deep-setting System. — This system is undoubtedly the best 
method of gravity creaming When properly carried on the 
fat can be removed so completely that 
no more than .2% of fat remains in 
the skimmed milk. It consists of put- 
ting milk into deep cans (ordinary four- 
gallon shotgun cans are usually em- 
ployed) immediately after the milk 
has been drawn from the cow. Then 
it is put into cold water, and generally 
cooled down to, and maintained at, a 

Fig. 69.— Cooley creamer temperature of about 55° F. The 
and elevator. .n . • i , , i c 

cream will rise m about twenty-tour 
hours. Better results can be obtained if the water is cooled 
down to about 40° with the use of ice-water. 

One reason why this system is in use so much, even in 
creamery localities is that the cream obtained is nearly always 
of a good quality. The farmer knows that unless the milk 
be cooled quickly, and maintained at a low temperature, the 
cream will not rise freely. For this reason the milk is syste- 
matically and thoroughly cooled, which is one of the great 
essentials in order to check the growth of the ferments in milk 




SEPARATION OF CREAM. 125 

and keep the milk in good condition. In many parts of the 
eastern United States, the deep-setting system is in general 
use. A special form of can is used. The can is simply an 
ordinary four-gallon can, about 8 inches in diameter and 20 
inches deep. It has a glass on one side near the bottom or near 
the top, which allows the reading of the thickness of the layer 
of cream. On each side of the glass is a graduated scale, which 
gives the reading in inches. In case the cream is being sold 
to a creamery, the hauler comes along, notes the depth of the 
layer of cream, and records the number of inches of cream 
opposite the patron's name. At the end of the month, or 
whenever the time for payment comes, the money is appor- 
tioned according to the number of inches of cream delivered 
by each of the patrons. No test for fat is made. This is what 
is known as the ''Cooley system/' and is used quite extensively 
in the East, especially in Massachusetts. 

While cream usually arrives at the creamery in a fair con- 
dition, there is the objection that the cream is always thin. It 
seldom contains any more than 18 or 20% of fat. 

No good explanation has yet been given why cream in a 
deep layer of milk at 40° F. should rise more quickly and more 
completely than in a thin layer at a higher temperature. 
* Arnold seeks to explain it by saying: 'MVater is a better 
conductor of heat than fat; hence when the temperature of 
the milk varies either up or down, the water in the milk feels 
the effect of the heat or cold sooner than the fat in the cream 
does. Therefore the cream is always a little behind the water 
in swelling with heat or shrinking with cold, thus diminishing 
the difference between the specific gravity of the milk and 
cream when the temperature is rising, and increasing it when 
the temperature is falling." 

This explanation is, according to Babcock,t not satisfactory. 
He says: " Though it is true that water is a better conductor 
of heat than fat, the small size of the fat-globules renders it 

* American Dairying, p. 210. 

•f Wisconsin Experiment Station, Bull. 18, p. 24. 



126 BUTTER-MAKING. 

impossible that under any circumstances there can be more 
than a small fraction of a degree of difference between the 
temperature of the fat and that of the milk serum. More- 
over, with the limits of temperature practical for a creamery, 
(90° to 40° F.), the coefficient of expansion of butter-fat is 
more than three times as great as that of water, so that in 
order to maintain the same relative difference in their specific 
gravities when the temperature is falling, the milk serum must 
cool nearly three times as quickly as the fat. In other words, 
when the milk serum has cooled from 90° to 40°, or 50° F., 
the fat-glabules should have lost less than 17°, and should 
still have a temperature of over 70° F., a difference between 
the temperature of milk serum and fat of more than 33°. Such 
a condition is manifestly impossible, but no less difference 
than this would cause the fat to become relatively heavier 
than at first, and would operate against the creaming." 

A low temperature increases the viscosity of the milk, 
and consequently it would seem that the resistant force of 
the fat-globules in their upward passage through the milk 
serum would be increased, and thus retard the creaming. 
Babcock maintains that fibrin is partially precipitated when 
milk is allowed to stand at a medium high temperature. The 
fibrin, when precipitated, forms a fine network of threads 
permeating the milk in all directions, similar to the network 
of fibrin in coagulated blood. It is possible to conceive that 
such a network would interfere with the rising of the fat-glob- 
ules, at comparatively high temperatures. The reason that 
fat-globules will rise more quickly and more completely in the 
deep-setting system than in the shallow-pan system, might 
be explained on this fibrin theory were it not for the fact that 
experiments conducted at the Cornell Experiment Station 
show that the setting and cooling of milk may be delayed 
long enough for this fibrin to form, without any effect upon 
the separation when set and cooled. 

Probable Explanation. — It is a well known fact in physics 
that most liquids, when present in the form of drops, increase 



SEPARATION OF CREAM. 127 

their surface tension when the temperature is lowered. Owing 
to this increase in surface tension, the hquid drops unite together 
at a low temperature much more rapidly than they do at a 
high temperature. For instance, two drops of molten iron 
unite much more readily just previous to soUdifying than 
they do while the temperature is higher, and the liquid more 
fluid. As the fat in milk is present in the form of small hquid 
globules, as mentioned previously, it seems probable that 
these fat-globules might have properties similar to those of 
the liquid mentioned above, and behave similarly in the milk, 
when set at low temperatures, in accordance with the deep 
setting method. If the fat-globules act in accordance with 
this theory, it seems probable that there is no real membrane, 
other than that resulting from surface tension, enveloping 
each fat-globule. If there were such a membrane, composed 
of albuminoid chiefly, then undoubtedly the fat-globules would 
not assume this property. 

With such a deep layer of milk the lower most fat-globules 
must evidently encounter a great many other globules as 
they rise. If the physical force mentioned does not facihtate 
the process of uniting the globules, they would partly unite 
without it. The more they unite in small bunches, or masses, 
the greater would be the tendency for them to rise, as explained 
previously, and more of the smaller fat-globules would be 
carried along. The bottom globules would tend to partly 
unite and form a filter, which passes up through the milk 
by the buoyant force, or force of levity. 

If this latter explanation holds true, then more of the milk 
constituents would be present in the cream from the deep- 
setting system than in the cream from the shallow-pan system. 
By comparing the cream raised by the shallow-pan system 
with that raised by the deep-setting system, before the cream 
has been removed from the milk, it will be noticed that the 
cream raised by the shallow-pan system appears to be much 
yellower than is that raised by the deep-setting system. This 
condition can only be due to the fact that the surface cream, 



128 BUTTER-MAKING. 

raised by the shallow-pan system, contains more pure fat. 
The fat, as it rises, does not have the same opportunity of 
uniting with so many other globules, owing to the comparatively 
shallow layer it has to pass through, and the temperature is 
not low enough to facilitate the uniting of the globules; that 
is, providing the fat-globules act the same as most other liquids 
at lower temperatures. 

Water-dilution Cream (Hydraulic). — When milk is diluted 
with water, the fat or cream rises much more rapidly and 
completely to the surface than it would in its undiluted form. 
A creaming-can is based upon this principle, and it was expected 
to combine quickness, efhciency, and simphcity. The sepa- 
rator consists simply of a tin can into which the milk is poured 
and then diluted with cold water. In a few hours the cream 
rises to the surface. Arrangements are usuahy made so that 
the skim-milk can be drawn off from the bottom of the can. 
While the diluted form of the milk apparently causes the 
creaming to be more efficiently and quickly done, it can readily 
be seen that in order to have a skimming efficiency equal to 
other methods of skimming, it must leave only about half as 
much fat, because the milk is diluted with about an equal 
volume of water. If the water-diluted skimmed milk contains 
.2% fat, then the same skim-milk in the undiluted form would 
contain .4 per cent fat. 

The water-dilution method of skimming practically spoils 
skimmed milk for feeding purposes. Skimmed milk which 
contains a fourth or a half of water, has been robbed of its 
essential relish to the calf, and it becomes necessary for the 
calf to consume too much volume in order to get the required 
amount of nourishment. 

This water-dilution system also gives more volume to 
handle. If farm dairying were conducted on a large scale, 
the method would not be practicable. 

Another objection is that the cream which results from 
this dilution method is seldom of good quality. Most well- 
water contains a multitude of micro-organisms which, when 



SEPARATION OF CREAM. 129 

added to the milk, produce putrefactive and undesirable results. 
Much well-water also is tainted to a greater or lesser degree. 
Especially is this so with water from shallow wells. Butter 
made from cream which has been diluted with water usually 
has a flattish poor flavor. 

The efficiency of separation of diluted and undiluted milk 
is reported by Wing * to be as follows : 

Diluted with 25% warm water set at 60° F. (39 trials), 0.77% 
fat in skim-milk; 

Undiluted, set at 60° F (30 trials), 1.00% fat in skim-milk 

Undiluted, set at 40° F (26 trials), 0.29% '' " 

Centrifugal Creaming. 

In the separation of cream by centrifugal machines, the 
same principle is used as in the gravity system of separation. 
The only difference is that in the centrifugal method the force 
which separates the cream from the milk is generated by 
artificial methods, and acts in a horizontal direction; in the 
gravity system the force which separates the cream from the 
milk is only that which results from the difference in the specific 
gravity of the cream and the skimmed milk, and the force 
acts in a vertical direction. The force generated in the sepa- 
rator is several hundred times greater than the natural force 
in the gravity method. For this reason the cream separates 
almost instantaneously after the milk has entered the separator 
and is exposed to the centrifugal force. 

Advantages. — The centrifugal separator has several advan- 
tages over the gravity method, which are apparent without 
detailed elaboration. In the first place, the range of tem- 
perature and condition of the milk at which the cream can be 
successfully separated is much greater than that for successful 
separation by the gravity method. Second, a much better 
quality of cream can be obtained by the centrifugal system, 

* Milk and Its Products, p. 105. 



130 BUTTER-MAKING. 

as the separation can be done before the milk gets old, while 
by the gravity method the time required for efficient separation 
is so long that the cream deteriorates more or less before it is 
removed from the milk. Third, by the centrifugal method the 
thickness of the cream can be regulated to suit requirements, 
while by the gravity method the thickest cream that can be 
obtained is about 20%. Fourth, by the centrifugal method 
many impurities and undesirable germs are removed, while in 
the gravity method the exposure to open air more or less 
impure is likely to contaminate the milk with taints, and also 
allows the germs to fall into it. Fifth, by the centrifugal method 
the skimmed milk is left in an unadulterated condition. The 
milk can be skimmed soon after milking, or after it has been 
delivered to the creamery, and thus be in the best possible 
condition for feeding purposes. Sixth, the centrifugal method 
permits of a more thorough separation of the fat. Butter-fat, 
as a rule, is too expensive to feed, when good and much cheaper 
substitutes can be had. 

History of Centrifugal Separators. — The first centrifugal 
separator was a very simple one. It consisted of buckets 
hanging on the ends of arms, or on the periphery of a rotating 
horizontal flat wheel which swung on a central axis. The milk 
was placed in the buckets and whirled for a time, and then 
the machine (if we may call it such) was stopped, and the 
cream removed in the same way as in the gravity system. 
This method of separation, according to J. H. Monrad,* had 
its origin in 1864. As early as 1859 Professor Fuchs of Carls- 
ruhe, Germany, suggested testing the richness of milk by swing- 
ing tubes holding the samples of milk. In 1864 Prandtl, a 
brewer of Munich, separated milk by such a device. In 1870 
Rev. F. H. Bond, of Northport, Massachusetts, worked out a 
method of separation which consisted of two small glass jars 
attached to a spindle making 200 revolutions per minute. By 
one hour's whirling the cream came to the top. 

* Dairy Messenger, Oct., 1892, p. 109. 



SEPARATION OF CREAM. 



131 



In 1875 Prandtl exhibited at Frankfort-on-the-Main a con- 
tinuous separator, which did not at the time attract much 
attention, due chiefly to the excessive amount of power needed 
to overcome the resistant force of the air. In 1876 a Danish 
engineer named Winstrup succeeded in improving the old 
bucket method. In 1877 Lefeldt and Lentch offered for sale 
four continuous separators with different capacities (from 110 
to 600 pounds of milk per hour). During that year also the 
first practical centrifugal creamery was established at Kiel, 
Germany. In 1877 Houston and Thompson of Philadelphia 
filed a patent for the continuous method of separation of cream 




Fig. 70. — First centrifugal separator. (From Dairy Messenger.) 



from milk. The patent was allowed in 1891. In March, 1877, 
Lefeldt and Lentch invented a separator similar in construction 
to the hollow bowl — a more recent type. This machine did not 
revolve at so rapid a rate as our modern machines do, nor 
did it have arrangements for continuous inflow and discharge. 
It was intermittent in its work, and it was necessary to stop 
at intervals to remove the cream and skimmed milk. 1879 
was the year which marked the greatest advancement toward 
the perfection of modern separators. The appearance of the 
Danish Weston, invented in Denmark, and the De Laval, in- 
vented in Sweden during that year, marked a great advance- 



132 



BUTTER-MAKING. 



ment in the separation of cream from milk. This led to con- 
tinuous milk and cream discharges, and consequently also to 
the continuous inflow of whole milk. These machines were 
of the hollow-bowl construction. 

Modern Separators. — Since the year when the Danish Weston 
and the De Laval machines were invented, many different 
types of separators with different contrivances within the bowl 
have been put upon the market. Baron Bechtelsheim, of 
Munich, is given the credit of having discovered that certain 




Fig. 71. — The United States separator. 

contrivances on the inside of the machine increase the efficiency 
and capacity of skimming. This discovery was made, accord- 
ing to J. H. Monrad,* in 1890. This invention was bought by 
the De Laval Company. 

The principal part of practically all the separators is a bowl 
rotating in a vertical position, with or without contrivances 
inside the bowl. Machines having a bowl rotating in a hori- 
zontal position are, so far as the authors know, not in use at 
the present time. Such a machine was once manufactured at 
Hamburg, Germany, and was called "Peterson's Centrifugal 



* Dairy Messenger, Jan. 1892, p. 9. 



SEPARATION OF CREAM. 



133 



Machine." Another German machine, called "The Page/' was 
also manufactured in the horizontal bowl style. 

From the above it will be noticed that four separate steps 
are recognizable in the evolution and improvement of separators : 

1. Revolving Bucket Centrifuge; 

2. Intermittent Hollow Bowl; 

3. Continuous Hollow Bowl; 

4. Continuous Separator with contrivances within the 

Bowl. 




Fig. 72. — The Simplex separator. 

The science and practice of separation of milk and cream 
have seemingly reached a high state of efficiency. It seems 
almost improbable, considering the many new improved sepa- 
rators on the market that any other great improvement could 
be made which would add a separate stage to the improve- 
ment of our best centrifugal milk separators of to-day. 

Classification of Separators, — Owing to the many different 
standard types of separators now on the market, it is impossible 
to describe each one in detail. For this reason the classifi- 



134 



BUTTER-MAKING. 



cation appearing below has been made. There are undoubtedly 
many other types, especially in foreign countries, with which 
the writers are not familiar, and which are not mentioned here. 
The following classification will, in some measure, illustrate 
the different makes of separators on the market to-day: 



Hollow bowl . 



Separa- 
tors. 



Farm sep- 
arators. 



/ De Laval (old style). 
\ Sharpies. 

r Omega, 
Cause milk to Empire. 
pass in thin , Davis. 
sheets vertical- 1 United States, 
ly in bowl. | National. 

[ Reid. 



Contrivances 
in bowl. 



Cause milk to 
separate into | 
almost h o r i - -{ 
zontal thin I 
sheets. 



Dairy Queen. 

De Laval. 

Peerless. 

Swea. 

Westphalia 
I (Cleveland). 
I Iowa. 
I, Skim-close. 



Creamery 
power 
separa- 
tors. 



Hollow bowl 



Contrivances in 
bowl. 



f Improved Danish Weston (Reid). 
\ Sharpies (old style). 
L De Laval (old style). 



milk to 1 United States. 
in thin I Simplex. 



Cause 
pass 

sheets verti- [ Sharpies (new 
callyinbowl. J style). 



Cause milk to ] 
separate in al- i De Laval, 
most horizon- j Springer, 
tal sheets. J 



Many of these separators which cause the milk to pass 
up and down in vertical sheets have the bowl contrivances 
corrugated, and perforated with holes so that the skim-milk 
and cream assume also a partly horizontal direction. 

Process of Separation. — From the illustrations, the structure 
of the more common types of separator bowls is readily 
understood. The whole milk may be made to enter at the 
bottom or top of the bowl when revolving. In the Sharpies, 
the milk enters at the bottom. The more common way 
is to have the whole milk enter at the top. As the 
milk enters the bowl and is exposed to the centrifugal force, 



SEPARATION OF CREAM. 



135 



it immediately begins to separate into three distinct layers. 
The centrifugal force acting in a horizontal direction forces 
the heaviest portions of the milk and the precipitated albu- 
minoids, ash, filth, and a multitude of germs over next to 





Fig. 73. — The Reid separator. 



Fig. 74. — The Sharpies separator. 



the wall of the separator bowl, and into a solid and more or 
less gelatinous layer, which is known as the " separator slime." 
In very impure milk this substance is so plentiful that it is 
likely to clog the separator in a very short time, and before 
much separation is accomplished it is necessary to clean out 
the bowl. The second layer is the skim-milk, while the cream, 
being the lightest, is forced to the center of the bowl and forms 
the third portion mentioned. There is no distinct line of 
demarcation between the layers of skimmed milk and cream. 
They overlap each other and form a sort of zone, rather than 
a sharp separation. The richest cream is nearest the center 
of the bowl, and gets thinner toward the outer portion of the 
bowl; consequently, by turning the outlet for the cream, or 
cream-screw, nearer the center of the bowl, the cream is increased 



136 



BUTTER-MAKING. 



in richness. Turning it away from the center causes the cream 
to be thinner. The skimmed milk that is forced clear to the 
circumference of the bowl contains the least fat, and con- 
sequently the skimmed milk is always first removed from this 
portion of the bowl. Usually the skim milk outlet is brought 
in towards the center of the bowl at one end through tubes 
extending from the circumference of the bowl. If this were 
not done, some difficulty would be involved in arranging a 





Fig. 75. — Showing "butter extractor" Fig. 76. — Showing cross-section of 
attached to De Laval separator. The De Laval separator bowl, 

butter extractor is not known to be 
in use now. 

receiving-pan for the discharged skim-milk. If the skim- 
milk were discharged near the circumference of the bowl, it 
would come out with a heavy force. Also, if the outlet for the 
skimmed milk were near the circumference of the bowl, a 
great deal more power would be required to run the machine. 
As the skimmed milk passes through the tubes towards the 
center it gives up its force. The nearer the skimmed-milk 
outlet can be brought to the center of the bowl, the easier 
will the machine run. 



SEPARATION OF CREAM. 137 

The size of the skimmed-milk outlet is usually made so 
that it bears a certain relation to the size of inlet, size of bowl, 
and to the speed of the machine. Most skimmed-milk outlets 
are made so as to discharge from .4 to about .9 or a little more, 
of the whole milk that enters the bowl. The remainder is 
the cream, which is forced to the center of the bowl and dis- 
charged through the cream outlet. 

Relative Amount and Richness of Milk and Cream 

Obtained. 

The conditions which affect the relative amount of cream 
may be said to be as follows: 

1. Regulation of the cream or skimmed-milk screw. 

2. Rate of inflow to the bowl. 

3. Speed of the machine. 

4. Temperature of the milk. 

I. Regulation of the Cream or Skimmed-milk Screw. — All 
modern machines, so far as known, have a device by which 
the relative amount of skimmed milk and cream can be con- 
trolled, and consequently the richness of the cream. Some 
machines have this device in the form of a cream- screw, and 
others as a skim-milk screw. The cream-screw in most of 
the machines has a hole on one side of it through which the' 
cream is discharged. If this screw is turned so as to make 
the hole nearer the center, then the cream will be richer and 
less in quantity. If turned away from the center, then more 
and thinner cream will be discharged. In some machines there 
is a skim-milk screw which serves the same purpose. The 
method then of regulating the relative amount of cream and 
skimmed milk works in just the opposite direction; that is, 
when thicker cream and less of it is wanted, then the milk-screw 
is turned so as to bring the skimmed-milk outlet nearer the 
circumference of the bowl. This gives more skimmed milk 
and consequently less cream. If thinner and more cream is 
wanted, then the screw is turned in. This causes more milk 
to flow out through the cream outlet. The Reid hand separator 



1";38 BUTTER-MAKING. 

is an example of this latter class. These two methods of regu- 
lating the thickness and amount of cream are the most common. 
It cannot be done while the machine is in motion. By some 
this is considered a drawback. 

Other separators have a device whereby the amount of 
cream can be regulated while the machine is in motion. For 
instance, on the improved Danish Weston, there is a screw 
attached to the skim-milk discharge-tube, by turning which 
the end or point of the tube can be made to be closer or farther 
away from the center, thus regulating the relative amount 
of cream and skimmed milk, and the thickness of the cream. 

2. Rate of Inflow. — The rate of inflow of milk to the sepa- 
rator has a large influence on the relative amount of cream 
and skimmed milk. The greater the inflow to the separator, 
the more and thinner cream will be obtained, and with a dimin- 
ished inflow the less and thicker cream is obtained. This is 
due to the fact that at a given velocity of the machine the 
skim-milk discharge remains practically constant. So, if 
more milk is turned on, the only place where the discharge 
can increase is through the cream outlet; and if the inlet is 
diminished, the cream will diminish until a certain time, when 
the amount of milk, which runs into the machine, equals the 
amount discharged through the skim- milk outlet, and then 
there will be little or no cream. This is aptly illustrated 
by Wing: " If the milk is turned into the bowl at such a 
rate that .8 escapes through the skim-milk outlet, we shall 
have .8 skim-milk and .2 cream. If, now, we reduce the rate 
of inflow by .1, we shall get. just as much skimmed milk as 
before, but only half as much cream ; or, if the inflow is increased 
.1, we shall get the same amount of skimmed milk and one 
and a half times as much cream." The completeness of sepa- 
ration will be the same so long as the separator is run within 
the range of its capacity. 

3. Speed. — The speed of the separator influences the rela- 
tive amount of the cream and skimmed milk only in so far 
as an increase in the speed of the bowl increases the capacity 



SEPARATION OF CREAM. 139 

of the skim-niilk outlet, due to a more rapid discharge 
through the skim-milk outlet. The slower the bowl re- 
volves the less skimmed milk will be discharged, and conse- 
quently, if the inlet is constant, more and thinner cream will 
be the result. It should be stated in connection with this 
that the efficiency of skimming depends to a large extent 
upon the speed, and if attempts are made to increase the amount 
of cream and decrease the percentage of fat in it, by lowering 
the speed, an abnormal amount of fat will be left in the skimmed 
milk. 

4. Temperature. — The temperature of milk usually does not 
influence the relative amount of milk and cream very much. 
The higher the temperature the more fluid the milk becomes 
and consequently, all other conditions being the same, shghtly 
more milk will run through at a high temperature than is the 
case with a lower temperature. This increase will show itself 
chiefly in the amount of cream, as the higher temperature 
has a greater relative effect upon the cream than it has upon 
the milk. By increasing the temperature of the milk, slightly 
more and thinner cream is obtained. 

Conditions Affecting Efficiency of Separators. 

I. Manner of Heating Milk. — Owing to the fact that fat- 
globules rapidly change their shape and property by exposing 
them to heat and excessive agitation, it is essential that care 
should be taken in heating milk previous to skimming. When 
fat-globules are heated they become more liquid, and if stirred 
very much the clusters of fat-globules break up more rapidly. 
The individual globules, if stirred violently, will break or sub- 
divide into several small ones. The higher the temperature 
of the milk, the more fluid the milk becomes, and the easier 
the separation. If milk is stirred violently, the individual fat- 
globules break up into smaller ones, which are separated from 
milk with difficulty. The following table * illustrates what 

* Hoard's Dairyman, Fort Atkinson, Wis. 



140 BUTTER-MAKING. 

effect the different degrees of agitation of milk has upon the 
efficiency of separation : 

Av. Fat 
No. of Per Cent 
Experi- in 
ments. Skim- 
milk. 

Milk heated in vat, not pumped 10 .117 

Milk heated in Pasteurizer, 200 revolutions of agitator per minute 8 .115 

250 " " " " " 3 .118 

300 " " " " " 8 .134 

350 " " " " " 2 .143 

400 " " " " " 7 .198 

500 " " " " " 4 .225 

Milk pumped by the turbine pump at 122° F 3 .129 

'< " " " " " " 64° F 3 .119 

" with the pump, effective at 122° 3 .117 

<< " " " " " " 64° 3 .115 

In the above experiments the diameter of the agitator in 
the Pasteurizer was 14 inches. The speed at the periphery, 
at 250 revohitions per minute, was 5 feet per second. 

It will be seen from the above table that the higher the 
speed of the agitator, the greater the difficulty in getting a 
complete separation. Besides the speed of the agitator in 
the heating apparatus, undoubtedly the shape of the Pas- 
teurizer is a factor in determining the efficiency of the 
subsequent separation. For instance, the milk in most hori- 
zontal Pasteurizers is, even at low speed, exposed to con- 
siderable agitation. 

If the milk is suddenly heated from a low temperature to 
about 80° or 90° F. and then skimmed, the heating does not 
facilitate the skimming process very much. It is essential 
that the milk should be exposed to this temperature for a 
considerable time. The fat-globules do not warm as rapidly 
as the milk-serum. This diminishes the difference between the 
specific gravity of the two substances, consequently complete- 
ness of separation becomes more difficult. If milk is heated 
to a high temperature, say, for instance, 170° F., then the 
separation will be sufficiently complete without exposing the 
milk for any length of time to that temperature. 



SEPARATION OF CREAM. 141 

Machines are now made, and are on the market, which will 
bring the milk, or the fat-globules in the milk, into such a 
condition that they cannot be separated from the milk. The 
process is called ''homogenization." It consists of bringing 
the milk under certain pressure, and then forcing it out through 
a special valve. This relief, through this special valve, causes 
the fat-globules to divide up into very minute ones. They 
divide up to such an extent that they cannot be separated 
from the milk by gravity methods, and it is impossible to get 
a complete separation by centrifugal methods. Homogeniza- 
tion of milk is carried on to some extent in Europe. The 
process practically insures uniform quality to the milk patrons 
in the distribution of milk in cities, and secures a more uniform 
consistency of the product. 

2. Condition of the Milk. — In order to get complete separation, 
and keep the separator in good running order, it is essential 
that the milk should be in as good physical condition as possible. 
Coagulated, slimy, or otherwise viscous milk separates with 
difficulty. When such milk is on hand it should not be mixed 
with the milk that is in good condition, as it might tend to coag- 
ulate more of the good milk, and the coagulated or slimy lumps 
are hkely to clog the separator. Such milk should be left 
until all the good milk has been separated. Then, if the coagu- 
lated or shmy milk is thoroughly stirred so as to reduce the 
lumpiness of it, it may be run through the separator success- 
fully. It is a good plan not to feed the separator quite so 
heavily when this quality of milk is being run through. By 
shutting off the inlet a little, it will usually run through without 
clogging. Milk containing impurities in suspension should be 
thoroughly strained previous to separation. 

Overfeeding the Separator. — When a separator is being 
overfed with milk there is a tendency for the machine to do 
less complete work. This is due to the fact that the more 
milk is being fed into the separator the less time it will be 
exposed to the centrifugal force. It is impossible to underfeed 
the separator as well. As has been mentioned before, the 



142 BUTTER-MAKING. 

inlet can be closed to such an extent as to cause nearly all the 
discharge to take place through the skim-milk tube. 

As a rule when the machine has been set so as to allow the 
milk to flow in at a certain rate, it will continue to admit prac- 
tically the same amount of milk all through the skimming 
period. Among the conditions which may alter the rate of 
inflow to some extent, are the amount of heat and the change 
of pressure, due to different amounts of milk in the receiving- 
vat. Temperature will slightly affect the rate of inflow. The 
higher the temperature, all other conditions being the same, 
the more milk will pass through the inlet. 

3. Speed. — All modern machines have a device by which their 
speed can be determined. Most speed indicators consist of a 
little wheel, which, when pushed up against the spindle of the 
separator while running, turns around and permits the calcu- 
lation of the speed of the separator. If the wheel on the speed- 
indicator turns 10 revolutions during ten seconds, the machine 
would turn 1000 times during the same time. During one 
minute the separator will run six times as many revolutions, 
or 6000, as ten seconds is one-sixth of a minute. Most speed- 
indicators are so adjusted as to turn one revolution for every 
100 revolutions of the machine. The higher the speed, the 
more thorough is the separation. Nearly all machines are 
balanced to do the best work at a certain definite speed, varying 
with different machines, and indicated in the directions for 
operating. It is essential that the machine should be brought 
up to speed gradually, and no milk be allowed to flow through 
it until after it has acquired its full speed. 

During the run, all machines are hkely to vary more or less 
in speed, owing to different causes. Pulleys are likely to shp 
on the shaft, and belts are likely to become loose, and thus 
cause variations in the speed. The steam pressure is Hkely 
to get low, and cause all of the machinery in the creamery to 
run more slowly. This cause, however, is not a very common 
one where belt separators are used. If the engine has an auto- 



SEPARATION OF CREAM. 143 

matic governor on it, the speed is usually quite uniform. Where 
steam-turbine machines are used, the speed of the machine is 
more hkely to vary with the different amounts of steam pressure 
on the boiler. With turbine separators it is very essential to 
keep an even steam pressure. Some turbine separators have 
a safety-valve attached to prevent too high speed. 

The reason why the prevention of a variation in speed is so 
essential is that a shght variation in the speed has a compara- 
tively large effect upon reducing or increasing the centrifugal 
force. The centrifugal force generated in a machine varies 
according to the diameter of the bowl, and according to the 
speed of the machine. The greater the diameter of the bowl, 
the less speed of velocity is required in order to get a certain 
force. The centrifugal force varies in direct proportion to the 
diameter of the bowl; that is, if the diameter of the bowl be 
doubled, then at the same speed, the centrifugal force has been 
doubled. The centrifugal force varies in quadratic proportion 
to the speed of the machine; that is, if the speed of the sepa- 
rator is doubled, the centrifugal force is increased four times. 
From this it will be seen that speed is a great factor in deter- 
mining the centrifugal force generated. It is not a good plan 
to have the diameter of the bowl too large, for the following 
reasons : A large bowl is more hkel}^ to be thrown out of balance; 
it is harder to keep on the bearings; and it is heavier and more 
unhandy to handle. For these reasons it is better to lessen the 
diameter of the bowl and increase the speed. This, of course, 
is true only to a certain limit. 

Steadiness in Running. — Smooth running of a separator is 
one of the first essentials. If a machine runs roughly, there 
will not be good separation, and it is dangerous to run it. The 
bowl itself is likely to jump out, or burst. The causes for 
unsteadiness in running are many. It may be due to a bent 
or sprung spindle; the machine not standing level; changing 
covers to bowls; using clamps which do not fit the bowl cover; 
unclean, worn-out bearings; condition of the bowl, and con- 
trivances inside the bowl; and dented and rusty bowls. Occa- 



144 BUTTER-MAKING. 

sionally it happens that a machine is run backwards. This is 
likely to cause the cover of the bowl to run off. 

Thickness of Cream. — The efficiency of skimming depends 
to some extent upon the thickness of the cream skimmed. 
Most separators, however, will skim within quite a wide range 
as to thickness. The richness of cream usually skimmed by 
separators is about from 25% to 50%. Most separators, how- 
ever, will do good skimming even if the cream contains as high 
as 60% fat. This, however, should be considered to be about the 
maximum, in order to get the best results from a separator. 

Slush in Bowl. — As has been mentioned before, there is 
always a thick, shmy substance which adheres to the bowl- 
wall. The composition of separator-shme is, according to 
Fleischmann, as follows: 

Water -., 67.3 

Fat 1.1 

Caseous matter 25 . 9 

Other organic substances 2.1 

Ash 3.6 

100.0 
At the center of the bowl, or along the axis which runs 
perpendicular in the bowl, there is always considerable cream. 
It is practically impossible to get all the cream out of the bowl, 
even if it is flushed with much water. The amount of slush 
varies somewhat with the different kinds of separators. For 
this reason, it is essential that it should be taken into con- 
sideration when the comparative efficiency of skimming of 
different separators is considered. When the test extends over 
a comparatively long period, and the milk skimmed amounts 
to several thousand pounds, then the bowl-slush does not affect 
the conditions for comparative results very much; but when 
the test is short, and only a hundred pounds of milk, or a similar 
amount, is skimmed, then the amount of fat left in the bowl- 
slush will have considerable influence upon deciding which one 
is the most efficient machine. 



SEPARATION OF CREAM. 145 

General Remarks. — In order to keep the separator in good 
running order, it must receive care. The belt should not be 
too tight, nor too loose. If too tight it is likely to bind, heat, 
and set the bearings of the separator. If too loose it is likely 
to slip, and to wear out more quickly. The machine should be 
well oiled. It is better to use a trifle too much oil than not 
enough. If a bearing is once heated, the machine will never 
run as well again. 

The bowl should be handled with great care. Bowls, or 
parts belonging to the bowl, can be kept from rusting by boiling 
them in water, or by steaming them thoroughly after they 
have been cleaned. If scalding-hot water is used before the 
milky portion has been washed off, the albuminoids will be 
scalded on to such a degree that it is difficult to get them off. 
This applies to all dairy and creamery utensils. Hot water 
is said to be best in which to dip tin or iron-ware after washing 
in order to keep them from rusting. If the bowl, pail, or 
whatever utensil it may be, is turned over to drain after being 
dipped in hot water, the heat taken up by the utensil will in a 
short time perfectly dry the apparatus. If the bowl is steamed, 
it should be heated thoroughly to make it dry quickly. 

If the milk supply gets short during the run, and it is neces- 
sary to run the machine without feeding milk, then the machine 
should always be flushed with luke-warm water. This will, in 
a measure, prevent clogging. Scalding -hot water should never 
be used for flushing the separator. The cream and skimmecl- 
milk tubes should be carefully cleaned, with the special wire 
provided for that purpose, each time the machine is washed. 
The contrivances on the inside of the bowl should also be 
handled with care so as not to injure them in any way. They 
should be treated with hot water, as mentioned above, in order 
to keep them from rusting. 

When the bowl is not to be used for some time, it should 
be oiled well so as to prevent it from rusting. It is easier to 
oil a separator bowl than it is to scour the rust off later on. 



CHAPTER XII. 

FARM SEPARATORS. 

The conditions affecting the efficiency of skimming and 
the relative amount of cream and skim-milk described under 
" Creamery Separation " apply to farm separators as well. The 
conditions under which the farm separators are operated war- 
rant a few separate remarks on this subject. 

Introduction of Farm Separators. — Small, or hand, separa- 
tors, have been manufactured for a good many years. It is, 
however, not until comparatively recent years that they have 
been numerous enough to be of commercial importance. The 
people in the Central West (Iowa, Kansas, Nebraska, Missouri, 
Minnesota, and Illinois) have been most prominent in intro- 
ducing farm separators. In the year 1894 hand separators 
were introduced in Iowa, but it was not until 1898 that they 
gained sufficient foothold to be of commercial importance. 
According to the Iowa Dairy Commissioner's report of 1898, 
there were then only 904 farm separators in the state of Iowa. 
Now, in 1904, there are more than 17,000 separators. Glancing 
over the statistics it will be seen that the rate of increase in 
hand separators during the years intervening between 1898 
and 1904 has been uniform and rapid. This proves that the 
dairy business is still in a transitional period, and the intro- 
duction of hand separators still on the increase. Such a time 
in any industry is always accompanied by more or less incon- 
venience, difficulty, and dissatisfaction. To receive a part of 
the butter-fat in the form of cream, and the other part in the 
form of milk, is undesirable. Under such a system it is always 
difficult to get milk or cream routes organized; proper sampling 

146 



FARM SEPARATORS. 



147 



becomes more or less difficult, and the quality of butter is 
harder to control. 

Reasons for Introducing Farm Separators. — It requires an 
investment of about $100 to purchase a hand separator. 




The Omega hand separator. 



Most of the butter made from hand-separator cream is of poor 
quality. Still, in the face of this, separators have rapidly -iu 
creased. It may be concluded that there must be some good 
reasons why farmers are continuing to invest in farm separators. 
There are undoubtedly many reasons why farmers prefer hand 



148 



BUTTER-MAKING. 



separators; reasons which are, to a large extent, confined to 
local conditions. Only a few of the chief and general reasons can 
be given here : 

(1) The farmer is able to skim the milk at once after it 
has been drawn, thereby enabling him to feed the milk while 





Fig. 78. — The Iowa hand separator. Fig. 79. — The De Laval hand separator 

(Baby No. 1). 

it is in a warm, sweet, unadulterated condition. If he hauled 
the milk to the creamery, the skimmed milk would be likely 
to come back in a sour and curdled condition, and at times 
watery. (In a well-conducted creamery these latter conditions 
do not exist.) 

(2) The high cost of hauling in many instances makes it 
almost impossible to get the milk to the creamery. Even if 
the roads are good, the distance to the creamery is frequently 
so great that it is impossible to get haulers, nor is it practical 
for every farmer to haul his own milk every day. Especially 
is this so during the busy season of the year. In the fall, 
when milk is scarce, it is almost impossible for the hauler to 



FARM SEPARATORS. 



149 



get enough milk to make it profitable. In many cases it is 
necessary to pay an excessive price for hauling milk. 

^\hen cream routes are established instead of milk routes, 
one hauler can usually cover as much territory as three could 





YiQ, 80. — Simplex hand separator and the different parts of bowl. 



under the milk system. Two thousand pounds of milk, testing 
4% and containing 80 pounds of fat, would represent approx- 
imately a load of milk. At 12 cents per 100 pounds, this 
would mean a cost of $2.40 for getting that much milk 



150 



BUTTER-MAKING. 



hauled. If the same amount of butter -fat were hauled in the 
form of cream, it could be gathered for about 1^ cents per 
pound of fat, or the cost of hauling in this particular case 
would be $1.20. Under the milk system it would be neces- 
sary to haul the milk to the creamery every day, while 
under the cream system it is usually gathered every other 
day in the summer, and every three days in the winter. It 
is usually considered that there is a saving of about 1^ to 2 




Fig. 81. — Sharpies separator and parts of bowl. 

cents per pound of butter-fat in hauling, by making use of the 
cream system instead of the milk system. This, of course, 
would vary according to local conditions. 

3. The use of hand-separators makes farmers more inde- 
pendent than they are under the whole-milk system. They 
are not compelled to support their local creamery unless they 
deem it advisable. They can ship their cream to any place that 
they may choose. If the butter from the hand-separator cream 
is going to be of as good quality as that made by the whole- 
milk system, the cream should be delivered as often as possible. 
Every day is preferable to every other day. In case frequent 



FARM SEPARATORS. 



151 



delivery is made, then it becomes quite essential for the farmer 
to patronize the local creamery, as very few farmers keep suffi- 
cient cows to get enough cream to pay them to ship by rail 





Fig. 82. — ^The National hand separator and parts of bowl. 

every day. Usually it does not cost much more to ship a 
can full of cream than it does to ship it half or three-quarters 
full. 



152 



BUTTER-MAKING. 




Objections to Farm Separators. — Under the present manner 
of carrying on the hand-separator system, the quahty of butter 
manufactured from the cream shipped into the central plants 
is much poorer than that made from whole milk. This is 
not due to any fault of the system, but to the poor care which 
the separator and cream receive. The sepa- 
rator on the farm is frecjuently kept in an 
unsuitable place. Often it is located in the 
barn. If the milk is separated in such a 
place it will absorb odors and undesirable 
taints. The cream is seldom taken care of 
properly after it is separated. The separators 
often are not cleaned well. A separator can- 
not be kept in good condition by simply 
flushing out the bowl with cold water at the 
end of each separation. It must be taken 
Fig. 83.— De Laval apart at the close of each skimming; have all 
hand separator. ^]-^g parts washed thoroughly in luke-warm 
water, and then scalded. The time and power it requires to 
skim the milk and to care for the milk is in many mstances 
considered objectionable to the system. 

Thickness of Cream. — The thickness of cream which most 
butter-makers at central plants prefer is cream containing 
about 30 to 40% of fat. Such cream is not thick enough 
to cause any inconvenience in sampling and weighing. It can 
be diluted with a good starter and ripened without getting it 
so thin as to produce unfavorable conditions for churning. 
By some it is deemed advisable to skim even thicker than this, 
up to 50%. Cream containing this much fat, however, is 
difficult to handle especially in winter, during cold weather. It 
gets so stiff that it is difficult to pour, and there is also danger 
of losing more or less cream through its adhering to the sides of 
the cans. 

A thick cream is advisable from the farmer's standpoint. 
The thicker the cream is, the more skim-milk he will retain 
on the farm for feeding purposes. It can also readily be seen 



FARM SEPARATORS. 



153 



that if thin cream is skimmed greater can capacity is necessary, 
and the express charges will be heavier than if the thicker 
cream were skimmed. Rich cream does not sour so rapidly 
as does thin cream. 




Fig. 84. — The Reid hand separator. Fig. 85. — Empire hand separator. 

The thickness of cream can be readily ascertained by the 
use of a Babcock test, which every farmer should have in his 
possession. A whole outfit for testing fat in cream or milk 



154 



BUTTER MAKING. 



can be had for about $8.00 from any creamery supply-house. 
By the use of such a test, the farmer can test his cream and 





Fig. 86. — Peerless hand separator and cross-section of bowl. 

skimmed milk. He can also test the milk of each individual 
cow in the herd, thereby ascertaining which ones are profitable. 




Fig. 87. — Agos hand tester. 

By the use of such a test on the farm, the farmer can test his 
cream daily, and compare results with those from the creamery^ 



FARM SEPARATORS. 



155 



thereby enabling him to detect any mistake which may happen 
at the creamery. 

Power for Farm Separators. — Hand-power is often men- 





1?/ 



Fig. 88. — The Dairy Queen hand separator. 



Fig. 89.— b'cales. 



tioned as an objection to farm separators. When a considerable 
quantity of milk is to be skimmed, it is certainly hard work 
to skim with hand-power. Windmills could not well be used 




Fig. 90. — Tread-power attached to United States hand separator. 



as they do not give uniform speed. The power must be steady 
and uniform. Farm separators are often run with tread- 
power. This kind of power is very applicable, and does not cost 



156 



BUTTER-MAKING. 




40% 



Fig. 91. — Showing the height to which cream free from air-bubbles must be 
raised in a pipette to get 18 grams of cream. It shows that to measure 
cream in a pipette is inaccurate in cream testing. (Iowa State Dairy 
Com. Report, 1903.) 



FA RM SEP A RA TORS . 



157 



anything after the tread-power has once been purchased. The 
power can be supphed by using different kinds of animals. 




Fig. 92. — Showing how the internal bowl devices of We.stphalia hand sepa- 
rator are washed. (X. Y. Produce R.e^^ew and American Creamery.) 

Sheep, goats, dogs, and bulls are used for this purpose. The 

process usually does not last very long, and it is not r-o]>i.|f.red 

heavy work. Steam is good power, but 

it is hardly ever obtainable on the farm. 

Small gasoline-engines are also used very 

successfully. 

The machine should always run smoothly 
in order to get efficient skimming. It should 
never be stopped and started with a jerk. 
Start it slowly and there will be less dan- 
ger of breaking any of the gearing parts. 
The bowl and inside parts should be kept 
from rusting as described previously on 
page 145. The bearings should be well Fig. 93.— Davis hand 
oiled. It is a good plan to have an extra 
bearing or two on hand, so that if one happens to wear 




158 



BUTTER-MAKING. 



out another one can be put in. The bearings should be 
cleaned at intervals. When kerosene is occasionally used on 
the bearings they do not need to be cleaned so often, because 




!FiG. 94. — Dairy utensils in the battered condition of the can on left and 
with tin off in many places inside, cannot be kept clean and should be 
discarded. (Kansas State Board of Agriculture Report No. 87, 1903.) 



it keeps them from gumming. The machine should be turned 
at the proper speed, as indicated in the directions. A thicker 
cream will result from rapid turning; consequently more 
skimmed milk will be obtained. Slow turning causes ineffi- 
cient skimming and thinner cream. 

Care of Cream on the Farm. — The first step in the produc- 
tion of good cream is clean milking. This can only be accom- 
plished when barn, cows, and utensils are clean. It is a good 



160 BUTTER-MAKING. 

plan to dampen a cloth, and wipe off the cow's udder and sides 
each time previous to milking. The milker should never 
wet his hands while milking. Dust should not be stirred up 
in the barn during milking, as the dust particles carry with 
them a large number of undesirable germs. When these settle 
in milk they are likely to produce taints. If cloth strainers 
are used they should be kept scrupulously clean. It is advis- 
able not to use them at all, as good sanitary wire-gauze strainers 
are inexpensive. 



Progeny of a 
single germ in © 
twelve hours 




Fig. 96. — Showing the effect of cooling milk on the growth of bacteria. The 
beneficial results of early chilling are readily apparent. (From Bill. 62, 

Wis.) 



If these conditions are complied with, and the separator 
is kept in a good clean condition, the milk will have compara- 
tively few germs in it. Some germs, however, will enter the 
milk, and in order to keep them from developing, it is essential 
to cool the cream or milk immediately. Low temperature 
retards and practically prevents the development of germ life. 
It is a well-known fact that when milk is kept cool, it will 
remain sweet much longer than if kept at a high temperature. 
Never mix two milkings or skimmings unless both are well 
cooled first. In order to cool cream quickly, it should be 
stirred during cooling. The ordinary four-gallon shot-gun cans 
are good and suital^le for keeping milk and cream. They have 
a large cooling surface in proportion to their cubical content. 



FARM SEPARATORS. 



161 



The milk or cream should be cooled as low as the water will 
cool it. It is well to cool it even lower than this if ice is ob- 
tainable. In keeping milk, the temperature should never go 




Fig. 97. 



-The condition of the cow shown in this cut is favorable for the 
accumulation of loose dirt. (Bui. 84, 111.) 



above 60° F. Cooling to 50° F., if it can be accomplished, is 
much more desirable for keeping milk or cream in good condi- 
tion. 



162 



BUTTER-MAKING. 



If considerable milk is handled, it is well to provide a milk- 
house. It should be built large enough to contain the sepa- 
rator, water-tank, and other utensils necessary for home butter- 




FiG. 98. — A clean cow. The dirt cannot adhere to this cow to so great an 
extent as to the one shown in Fig. 97. (Bui. 84, 111.) 



making, such as a churn and butter-worker. There should be 
plenty of windows on all sides to give good ventilation. The 
water-tank should be connected directly with the well, so that 




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FARM SEPARATORS. 167 

the water can be pumped directly to the tank holding the milk 
and cream. From this place the water can be run out into 
the stock-tank. This arrangement allows the milk to be kept 
at the lowest possible temperature. 

It is just as essential to cool the milk during the winter 
as it is during the summer. By pumping water through this tank 
practically all the time, the water in the tank will be kept from 
freezing. It is well to keep the surface of the water higher 




Fig. 103. — ^The average weight of dirt which falls from muddy udders dur- 
ing milking is ninety times as great as that which falls from the same 
udder after washing, and when udders are slightly soiled it is twenty- 
two times as great. (Bui. 84, 111.) 

than the surface of the milk in the can. This will prevent the 
milk from freezing so easily. If the cold is too severe, a tank- 
heater can easily be secured which will moderate the tem- 
perature a trifle. 

Disposition of the Cream. — There are two ways of disposing^ 
of cream on the farm: (1) selling it to creameries or other 
parties, and (2) making it into butter on the farm. The former 
method is usually the most advantageous. Creameries, as a 
rule, are better equipped to control the quality of butter. The 
price per pound of butter-fat is usually about 2 cents below 
''New York Extras." A few of the best co-operative cream- 
eries are able to pay more than that. 



FA RM SEP A RA TORS. 



169 



Shipping of Cream. — If cream is sent or shipped to cream- 
eries and central plants, it is essential that it be delivered as 
frequently as possible, and that it be delivered in cans which 
will help keep it in good condition. If cream is to be shipped 
any great distance and be exposed to the sun, it is advisable to 
use special jacketed cans, which retard the transmission of 
heat. It is a good plan to cover the cans with a wet sack 
or cloth during the summer, and the use of a dry sack on 





Fig. 105, — ^The Bulil milk and cream can. Fia. 106. — A barrel churn. 



the outside in the winter often prevents the cream from 
freezing. 

Making Butter on the Farm. — If cream is kept in good 
condition and proper skill is applied, the best of butter can 
be made on the farm. Theoretically, better butter can be 
made on the farm than at the creamery, because all conditions 
can be controlled better. This is not so in creameries. One 
can of bad cream mixed with a quantity of good cream is likely 
to contaminate and injure the whole lot. The cream which 
is to be made into butter on the farm should be ripened, or 
soured, properly before it is churned. In creameries, starters 



170 



BUTTER-MAKING. 



are used to set up a quick and desirable fermentation in the 
cream. Conditions are usually such on the farm that it is not 





Fig. 107. — The Davis swing-churn. Fig. 108. — Sanitary glass milk- 
bottle and cap for same. 

convenient and practical to use a starter. In the summer the 
cream can be lifted out of the cold water the morning previous 




Fig. 109. — Skinner butter-worker. 

to churning, and it will sour during the day. In the evening, 
or when it has soured, it can be set back into the water to cool. 



FARM SEPARATORS. 



171 



The next morning it is ready for churning. In the winter the 
cream can be soured by warming it up or keeping it in a warm 
place. If some good sour milk is on hand, it might be added, 
and the cream will sour much quicker. It is very essential that 
the cream can be cooled to a low temperature (50° F.) and left 





Fig. 111. — The Cherry jacketed 
cream can. 



Fig. 110. — Milk or cream can 
with agitator. 




Fig. 112. — The Jersey can-brush. 



at this temperature for at least two hours before it is churned; 
otherwise the butter is likely to be greasy and salvy. Color 
and salt to suit the market and season. About three-fourths 
to one ounce of salt to one pound of butter usually gives good 
results. 

If a local trade can be secured, it is not necessary to pack 
it into tubs. Earthen jars are good to keep butter in. If no 



172 BUTTER-MAKING. 

local trade can be secured, and it is essential to ship the butter, 
20- or 30-pound tubs should be used. If a good quality and 
constant supply of butter can be secured throughout the whole 
year, it is an easy matter to find an excellent market for butter 
at hotels or good restaurants. (For a more detailed discus- 
sion of butter-making, see Chaps. XVI and XVII.) Putting up 
butter in prints and wrapping them in parchment paper which 
bears the maker's name usually increases its value. 



CHAPTER XIII. 

PASTEURIZATION. 

Definition. — The word pasteurization has its derivation from 
Pasteur, a French scientist. Pasteurization consists in heat- 
ing milk somewhere between 140° F. and 212° F. This kills 
practically all germs in a vegetative state. Since most of them 
are in a vegetative condition, the process kills almost all the 
organisms. The heating is followed bj^ rapid cooHng. ''Sterili- 
zation" is a word which is some times used incorrectly in con- 
nection with pasteurization. Sterihzation means that milk or 
any other substance has been heated so often or to such a high 
temperature as to entirely destroy every living micro-organism 
present. In order to get a substance thoroughly sterilized 
without heating under pressure, it is essential that it be heated 
about thirty minutes on each of three or more successive days. 
Pasteurization in the dairy industry was introduced by Pro- 
fessor Storch of the Royal Experiment Station, Copenhagen 
Denmark. 

Methods of Pasteurization. — 

(1) Intermittent. 

(2) Continuous. 

1. Intermittent pasteurization is usually accomplished in 
vats or cans. It is used nearly exclusively when pasteurization 
is practiced on a small scale, such as preparation of starters 
in creameries, pasteurizing cream and milk on the farm, etc. 
Intermittent pasteurization is as efficient, and undoubtedly more 
so, than the continuous method. The substance pasteurized 
is usually exposed to the high temperature a longer time than 
it would be by the intermittent system. In the continuous 

173 



174 



BUT TER-MA KIXG, 



method of pasteurization the substance pasteurized is exposed 
only to a sudden temporary heat. 

The intermittent process of pasteurization tends to drive 
off more of tlie undesirable taints present in the milk or cream. 
This is especially true when stirred occasionally. If heated too 
long the cooked flavor is hkely to be more pronounced than 
when the intermittent system is used. If exposed very long 




kirn Milk Inlet 



Skim ililk Tank 



>J 



Fig. 115. — Scheme for pasteurizing skim-milk by the use of exhaust-steam 
direct. (Creamen,- .Journal, by W. P. McConnell. ^Minn. 

to the high temperature and stirred excessively during the 
intermittent pasteurization, the butter-fat tends to melt and 
run together, and show itself on the top of the cream in the 
form of an oily layer. 

2. The continuous method of pasteurization is more practical 
for large amoimts of milk or cream. It is used almost viithout 
exception in pasteurizing cream, whole milk, and skim-milk 
at creameries. Xeither one of the two systenxs destroys spores. 
The intermittent svstem is the most effective becaijse both 



PASTETSPdZATIOS. 175 

time and temperature are mider comrol. Various pasteuriz- 
ing machines are in use. and it is not within the pro^-ince of 
this work to recommend any machine. A few words in regard 
to the principles which affect proper pasteurization will serv^e 
a better pui-pose. 

Selectiox of Pastzueizers. 

Improper pasteurization is worse than none at all. If 
pasteurization is done at aU, it is essential that it be properly 
accomplished. 

There are tT\-o things to be sought when purchasing a pas- 
teurizer: \iz., (1) durabihty and capacitA', and (2; economic 
efficiency. 

1. Durability and Capacity. — The structure of most pas- 
teurizing machines is simple and substantial. They do not 
wear out like a complex piece of machinery.'. It is essential 
that the machine be strongly made. Heating-waUs and other 
portions should be made heavy enough to be consistent with 
its use. and of a substance which wiU conduct heat rapidly. 
Xearly aU the types of pasteurizers are made in different sizes 
to suit the demands. 

2. Economic Efficiency. — Obtaining efficient pasteurization 
economically is the most important question. It is important 
in this connection because it depends upon so many conditions 
which the operator has under control. The degree of con- 
ducti^ity of heating-surface during operation, may in one sense 
include most of the essential factors which affect pasteurization. 
This in turn depends upon a number of conditions which are as 
follows : 

(1; Kind of material from which the heating-surface is 
manufactured. 

(2; Degree of adh^veness of milk or cream on heating- 
surface. 

(3j Thickness of layer of condensed steam, on steam side of 
heating-surface. 

(4; Difference in temperature on each side of heating-STirface. 



176 BUTTER-MAKING. 

(5) Proper utilization of steam turned into the pasteurizer. 

(1) Heating-surface. — It is a well known fact that some 
metals will conduct heat better than others. The relative heat 
conductivity of the two substances used chiefly for pasteurizers, 
viz., copper and tin, is .918 and .145 respectively. This 
means that copper will conduct heat nearly seven times faster 
than tin of the same thickness. 




Fig. 116. — The Reid pasteurizer. 

In connection with this it should be mentioned that stability 
and durability of the substance must also be taken into con- 
sideration. A heating-surface made from copper may be nearly 
seven times as thick as that made from tin, and still transmit 
as much heat as the tin surface. From this it can be seen that 
a heating wall made from copper can be increased shghtly in 
thickness, and thus aid in stability, without affecting the degree 
of heat conductivity of the wall very much. The heating- 
surface must be strong enough to withstand a slight steam pres- 
sure, otherwise the heating wall is likely to collapse or cave 
in in case of slight variation in the steam pressure. It is not 



PASTEURIZATION. 



177 



an uncommon occurrence to have the heating wall of a pasteur- 
izer burst. This could be prevented by connecting a safety, or 
pressure, valve, to the pasteurizer. 

(2) Degree of Adhesiveness. — Roughness, due to either 
defects in the metal itself, or to milk or cream being burned 
on the heating-surface, is a serious defect. Such a condition 




Fig. 117.— The Simplex regenerative pasteurizer (apart). 



causes particles of milk or cream to move very slowly over the 
heating-surface; it tends to roll in much the same way as 
drops of hquids do when caused to flow over a slanting dry 
rough surface. As a consequence more and more casein will 
adhere. The thicker the layer of foreign matter is on the 
heating-surface, the greater the difficulty in getting the greatest 
efficiency from the pasteurizer. 

It is important that the milk or cream be forced over the 
heating-surface with greater rapidity than could result from 
its own gravity. On heaters or pasteurizers, where milk flows 



178 



BUTTER-MAKING. 



over the heating-surface only by force of its own gravity, a 
heavy layer of curd usually adheres. This is due to the fact 
that certain portions of the milk are exposed to the excessive 
heating too long, while if caused to move rapidly it does not 
remain in contact with one portion of the heating-surface long 
enough to cause it to adhere to so great an extent. 




Fig. 118. — ^The Simplex regenerative pasteurizer (assembled). 

The condition of the milk or cream has some influence upon 
the degree of adhesiveness of curd on the heating-surface. 
Sour and coagulated milk adheres or burns on to a greater 
extent than does milk or cream in good condition. This is 
evidently due to the lesser fluidity of the sour milk, and, as a 
consequence, it does not move over the heating-surface sO' 
rapidly, and therefore burns on. Milk which contains a great 
deal of air or scum also adheres to the heating-surface much 



PASTEURIZATION. 



179 



more readily than milk containing less air. If pumps are used 
for pumping the milk, it is well to admit as little air into the 
milk as possible. This can be accomphshed by keeping plenty 
of milk in the tank which feeds the pump, or by having a float 
which will close the inlet to the pasteurizer as soon as the tank 
is emptied. If the speed of the agitator in the pasteurizer 
is great enough, the scum is forced towards the center. For 




Fig. 119. — ^The Jensen pasteurizer. 

some time it was thought that only the best sweet milk could 
be pasteurized by the intermittent process of pasteurization. 
It is well known that when a sample of milk reaches a certain 
degree of acidity it coagulates upon heating. It was thought 
that by the continuous method of pasteurization this would 
interfere with getting proper results. Experiment, however, 
shows that the coagulated sour cream and milk can be suc- 
cessfully pasteurized, but it is still a fact that the better con- 
dition the milk or cream is in, the easier it can be pasteurized 



ISO 



B UTTER-MA KING. 



and the better the results are. If pasteurization is not prop- 
erly conducted, often the sour milk and cream coagulate and 
get very lumpy. This takes place chiefly when pasteurization 
is attempted at a comparatively low temperature, at a slow 
rate of speed of the agitator in the pasteurizer, and when there 
is about from .3% to .4% acidity in the cream or milk. Sour 
thin cream — less than 28% fat — does not pasteurize successfully. 
In case there is any danger of sliminess taking place during 
pasteurization, the heat should be applied as cfuickly as possible. 

Only a thin layer of cream 
should be exposed to the 
heating-surface at one time. 
Flashy, c|uick heat tends to 
prevent this slimy condition. 
The speed of the stirrer should 
be increased, if possible, when 
such cream is being pasteur- 
ized. 

By greasing the inside of 
the pasteurizer, or the heat- 
ing-surface, a trifle previous 
to pasteurization, the burning- 
on can be prevented in part. The casein that adheres can 
be more easily removed than if no grease were used. 

(3) Thickness of Layer of Condensed Steam. — At first glance 
one might come to the conclusion that the small amount of 
steam which is constantly being condensed upon and adhering 
to the steam side of the heating-surface is not sufficient to 
cause any difference in the efficiency of the pasteurizer. Ex- 
periments conducted by Dr. Storch of the Royal Experiment 
Station, Copenhagen, Denmark, show that this condensed steam 
greatly resists the transmittance of heat. The comparative 
heat conductivity of water and copper is .0016 and .9 respec- 
tively, as found by Dr. Storch. It will thus be seen that copper 
is 600 times as good a conductor of heat as water is. This would 
mean that a quiet layer of water 3 millimeters in thickness 




Fig. 120. — The ^Miller pasteurizer. 



PA S TE URIZA TIOX. 



181 



would have the same resistance to heat as a layer of copper 
2 meters in thickness. Consequently a very thin layer of water 
or condensed steam on the sides of the heating-wall would 
greatly interfere with the economic efficiency of a pasteurizer. 

In order to overcome this difficulty drip-rings were circled 
round the drum of the pasteurizer at intervals on the steam side 
of the heating-surface. The first rings put around the pasteurizer 
were narrow smooth bands. These cUd not give entire satisfac- 
tion, as the condensed water from the top rings would drip on 
the edge of the lower ones, and cause the water to splatter over 
the side of the heating-wall. Another kind of ring was then in- 
vented, which 
was thin, nar- 
row, and saw- 
teeth-like in 
shape. These 
rings were fast- 
ened to the 
heatmg-wall at 
proper inter- 
vals at an angle 
of 45°. The 
rings were so 
arranged that 

the drops of condensed water escaping from the end of each saw 
tooth would fall in the hollow between the teeth in the lower rings 
and thus prevent any splattering of the water against the heating- 
wall. These contrivances greatly increased the efficiency — as high 
as 48% — and the capacit}' of the pasteurizer experimented upon. 

(4) Difference in Temperature on Each Side of the Heating- 
surface. — The difference in the temperature on each side of the 
heating-sm'face has a great effect upon the rapidity ■\,\'ith wliich 
the heat passes through the wall. The lower the temperature 
is on the milk side the more rapidly does the heat pass through; 
and the higher the temperature of the milk is, the pressure on 
the steam side being the same, the more slowly the heat passes 
through the heating-wall. This would at first lead us to be- 




The Farrington pasteurizer. 



182 BUTTER-MAKING. 

lieve that the last few degrees the milk is being heated are the 
most expensive; but if the steam is properly guarded from 
being condensed, or wasted, it does not cost any more to heat 
the milk the last few degrees than it does to heat the first degrees. 
While the temperature on the milk side is low, much more 
steam is consumed, and it is also used more rapidly. During 
the last heating of the milk or cream less steam is being con- 
densed and the condensing proceeds more slowly. 

When the temperature on the steam side is 220° F. and on 
the milk side is 40° F. during the same time, twice as nuich 
heat will pass through the heating wall as if the temperature 
of the milk side were 130° F. In the first case the difference 
in temperature on both sides would be : 220-40= 180° F. In 
the second instance it would be: 220-130 = 90°. F. 

(5) Proper Utilization of Steam Turned into the Pasteurizer. 
— The cost of pasteurization will evidently vary under different 
conditions and with different kinds of pasteurizers. In order 
to reduce the cost of pasteurization to the mininmm, it is 
essential that all steam turned into the pasteurizer be properly 
utilized. The pasteurizer, as weh as the steam-pipes, should 
be properly insulated in order to prevent unnecessary conden- 
sation of steam. According to experiments carried on by 
Dr. Storch, all steam contains more or less air. By making 
a device on the pasteurizer for the escape of this air better 
results were obtained. By the use of such a vent it was made 
possible to heat 1890 pounds of water from 52° F. to 185° F., 
while without this air device, and with the same amount of 
heat, only 1467 pounds of w^ater were heated. That is, by 
this device he made a gain of 30% in the heating efficiency 
of the pasteurizer. The contrivance used was simply a pipe 
attached to the bottom of the pasteurizer and extending down 
below the pasteurizer about 2 feet, then turned or bent, and 
brought up vertically a few inches above the bottom of the 
pasteurizer. The mouth of the pipe was then turned over. 
This pipe accomplishes two purposes. It removes condensed 
water from the pasteurizer, and also the accumulated air. It 



PASTEURIZATION. 183 

is also essential that the pasteurizer should not leak. All the 
steam turned into the pasteurizer should be condensed before it 
is allowed to escape. 

The Cost of Pasteurization. — Dr. Storch in his 43rd report of 
the Royal Agricultural Experiment Station, at Copenhagen, 
Denmark, reports that it requires 80 pounds of steam to heat 
1000 Danish pounds of milk from 40° C. to 85° C. This would 
be equivalent under American conditions to about 90 pounds of 
steam to pasteurize 1000 pounds of milk from 90° F. to 185° F. 

According to good authority it takes 1 pound of lump coal 
to produce 6 pounds of steam. Calculating from this, it will 
take 15 pounds of coal to produce 90 pounds of steam. If 
coal costs S4.00 per ton, the cost of 15 pounds of coal would 
be 3 cents. If the milk tests 3.6% fat, and calculated on 
one-sixth overrun, the 1000 pounds of milk would produce 
about 42 pounds of butter. The cost of pasteurizing the milk 
producing 42 pounds of butter is then 3 cents, and the cost 
of pasteurization per pound of butter would be .07 of a cent. 

Taking into consideration the cost of coohng, and counting 
on about .03 of a cent for leaks involved during the process, 
the cost of pasteurizing per pound of butter would be about 
.1 of a cent. As a rule, the major portion of the coohng is done 
with water, which at most creameries costs little or nothing. 
For this reason the cost of cooling has been omitted. 

Advancement of Pasteurization. — During the last few years 
pasteurization has gained favor with the American creamery 
operators. It has been thoroughly demonstrated that if the best 
product is to be manufactured it is absolutely essential that the 
operator have complete control of the fermentations in the 
cream or milk. This control of the fermentation can best be 
accomphshed by the process of pasteurization. Pasteurization 
has been gaining favor with the creamery operators owing to 
its own merits. The Danish Government compelled the pas- 
teurization of milk or cream as a safeguard against tuberculosis. 
It was found not only that the system was efficient in this 
respect, but also that it produced a more uniform product, with 



184 BUTTER-MAKING. 

better keeping qualities. At the present time nearly all of the 
central plants are pasteurizing their cream to a greater or less 
extent. 

Advantages of Pasteurization. — The advantages of pasteur- 
ization are many, but the chief ones are as follows: 

(1) It enables the butter-maker to produce a uniform 
quality of butter. If most of the germs are destroyed by 
pasteurization, and a pure culture added to the cream, the 
ferments added will be in full control. If nothing but a desir- 
able kind of germ is added, it follows that the product will be 
uniform in quality In this way practically the same results 
can be obtained from day to day. 

(2) It eliminates many of the undesirable taints in the milk. 
Especially is this effect noticeable during the fall, when cows 
are liable to eat weeds that taint the milk. No matter how 
w^ell milk has been taken care of, it usually contains taints 
which, when pasteurized will be partially eUminated from the 
milk. 

(3) It destroys most of the germs. This is important 
for two reasons. It destroys most of the germs which effect 
the quality of the butter, and it also destroys the pathogenic 
germs, thus preventing the spread of diseases, such as tuber- 
culosis, typhoid fever, etc. 

(4) The butter-maker can control the fermentation in cream 
much more easily when pasteurization is employed. It has 
been demonstrated that the quality of the butter depends 
in large measure upon the kind of fermentation. When the 
fermentation in the cream is thoroughly controlled, a better 
quality of butter can be produced. When the milk is in first- 
class condition, fully as good butter can be produced without 
the use of pasteurization, but it does not keep so well. Milk 
may appear to be in good condition, and yet at the same time 
contain germs which are detrimental to the quality of the 
butter. 

It is at the present time a matter of dispute whether milk 
and cream in a really sour and poor condition is benefited 



PASTEURIZATION. 185 

much by pasteurization. The flavor of the butter made from 
such pasteurized cream is usually not improved very much. 
However, the keeping quality of butter made from poor cream 
pasteurized is usually better than if no pasteurization had been 
employed. If the inferior quality of cream and milk can be 
pasteurized, neutralized with an alkali, such as powdered chalk 
or bicarbonate of soda, then inoculated with a desirable species 
of bacteria and re-ripened, the quality of butter can be im- 
proved several points. But experiments carried on at the 
Iowa Experiment Station indicate that the improvement in the 
quaUty of butter is not very permanent. Immediately after it 
has been made there is a very distinct improvement in the 
quality of the butter from such cream, sometimes as much as 
five points. But for some reason butter from cream that has 
been neutralized in such a way does not seem to keep well. 
Some days after its manufacture it begins to lose decidedly in 
flavor and to assume a very rank condition. For this reason 
this method of treating poor cream has not been generally 
advocated. The deterioration that takes place in such butter 
after standing seems to be due to chemical cha,nges rather 
than to biological changes. The butter referred to was kept 
in a refrigerator at a temperature of about 50° F.; if the rancid 
flavors were due to the growth of micro-organisms, they should 
not reveal themselves in so short a time. 

(5) Pasteurization increases the keeping quality of butter. 
This is one of the greatest advantages of employing pasteuriza- 
tion in butter-making. The advantage of keeping butter from 
the time of large supply and small prices to the time of small 
supply and higher prices, makes pasteurization in butter-making 
of vital importance in improving the keeping quahties of butter. 
Butter made from good pasteurized cream and washed in pas- 
teurized water will keep about twice as long as butter made 
from the same kind of cream not pasteurized and washed in 
unpasteurized water. 

(6) If milk is pasteurized previous to skimming, closer 
skimming can be obtained than if the milk were heated to a 



186 



BUTTER-MAKING. 



comparatively low temperature. The reason for this has been 
previously explained. 

Disadvantages of Pasteurization. — The cost and additional 
trouble involved in pasteurizing are undoubtedly the chief 
disadvantages that could be brought up against pasteurization. 
As was calculated above, the cost of pasteurization, after the 
pasteurizer has once been purchased, is only .1 of a cent per 
pound of butter. This cost would be reduced considerably 
if the cream only were pasteurized, and increased if the cream 
and skim-milk were pasteurized in separate machines. The 



Score 


1st 

week 


2nd 
week 


3id 

week 


4th 
week 


5th 
week 


Gth 
week 


7th 
week 


8th 
week 


Oth 
week 


10th 
week 


11th 
week 


12th 
w^eek 


13th 
week 


Uth 

week 


SCO 


96 






























90 


94 






























94 


92 


y^ 































92 


90 






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[^ 








^ 


■i;'«ff 












90 


88 










X^ 




















88 


80 










^ 


h'; 










^- 








86 


84 














^^> 

^s"'' 


/ 










N^ 




84 


82 
















N 










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83 


80 
















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s^ 












80 


rs 


















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X 










78 


76 




















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76 


74 































74 



Fig. 121. — Comparison of deterioration of butter made from pasteurized 
cream and wash-water to that made from unpasteurized cream and 
water, illustrated graphically. (Bui. 71, Iowa.) 

initial cost of the pasteurizer is the great momitain to over- 
come in the introduction of pasteurization in creameries. 

When pasteurization is employed in butter-making, it is 
absolutely essential that the greatest degree of skill and in- 
telligence be applied. If care is not taken pasteurization is 
likely to produce a poorer quahty of butter than is the case 
when no pasteurization is employed. Especially is this true 
when sour or abnormal cream and milk are being pasteurized, 
and little or no starter is used. 



CHAPTER XIV. 

CREAM-RIPENING. 

Definition. — By cream-ripening we mean the treatment 
cream receives from the time it is put into the ripening-vat 
until it is put into the churn; and also the chemical, biological, 
and physical changes cream undergoes during the same time. 

Objects of Ripening. 

(i) To Produce Flavor and Aroma. — The chief object of 
cream-ripening is to secure the desirable and dehcate flavor 
and aroma which are so characteristic of good butter. These 
flavoring substances, so far as known, can only be produced by a 
process of fermentation. It is a well known fact that the best 
flavor in butter is obtained when the cream assumes a clean, 
pure, acid taste during the ripening. For this reason, it is 
essential to have the acid-producing germs predominate during 
the cream-ripening; all other germs should if possible be 
excluded or suppressed. 

It has not yet been proved that any one particular species 
of bacteria is responsible for the production of the flavors, but it 
is agreed by all that the flavoring substances developed during 
the ripening of cream are decomposition products of bacterial 
growth, and that the types producing the lactic acid are the 
most desirable ones to have present. There are a great many 
bacteria in milk and cream which ^ill produce acid. Over one 
hundred species have been studied and described. There seems, 
however, to be a comparatively few of those which produce 
the best results. 

187 



188 



BUTTER-MAKING. 



It seems that during cream-ripening the development of 
acid, aroma, and flavor go hand in hand. This does not neces- 
sarily indicate that they are produced by the same cause. It 
is possible that the flavor and aroma substances are chemically 
produced from the various by-products of the germs. 

Bacteriologists do not agree as to what species of bacteria 
is responsible for the high quahty of flavor and aroma of butter. 
Conn * claims that the germs which act upon the nitrogenous 



/•H"^ 




Fig. 122. — The McArea\y cream- 
ripening vat. 



Fig. 123. — The Miller cream-ripening 
vat. 



matter of milk are associated with the lactic-acid-producing 
bacteria in the production of desirable butter flavors. Weig- 
man asserts that the best results are obtained when a variety 
of species work together in the cream. He has isolated a single 
species of germ which produced alcohol and lactic acid as 
by-products, and which, according to experimental evidence 
deduced by him, is capable of producing the dehcate butter 
flavors. Freudenrich has also studied a species of germ which 
produced alcohol and lactic acid as by-products, and was able 
to produce the characteristic butter flavors. Eckles has studied 
this question of flavor production during cream-ripening. He 
comes to the conclusion that the flavor and aroma substances 



* Storr Station, Conn. 



CREAM RIPENING. 



189 



developed during creani-ripening may be produced by a variety 
of acid-producing bacteria. He asserts that of the species 
tried the most common milk-souring organism (Bacterium lac- 
tarii) gave the most satisfactory results as a culture for ripen- 
ing cream. S torch, who has perhaps studied this question 
more than any one else, maintains that the germs producing 
lactic acid are essential to good cream-ripening, and that the 
flavor and aroma products are the results of the joint action of 
a great many species of lactic-acid-producing germs. Tiemann * 
finds that an addition of a small amount of hydrochloric acid 
to the cream does not produce the characteristic flavor, and in- 




FiG. 124. — The Wizard cream-ripening vat. 

dicates that the process of fermentation is necessary to get 
the proper flavors. Dean, of the Ontario Agricultural College, 
has recently reported that the flavoring substances can be 
developed in the starter, then added to the cream. The re- 
sulting butter has as good or a trifle better flavor than that 
which undergoes a process of fermentation by ripening in the 
usual way. 

From the investigations quoted above it will be seen that 
there is some doubt yet as to the specific origin of the flavor 
and aroma substances developed during cream-ripening. It 
is also not known for certain just what those flavoring sub- 



* Milch-Zeitung, Vol. 13, p. 701. 



190 



BUTTER-MAKING. 



stances are. They are evidently volatile, ether-like compounds, 
which are produced by bacterial growth during the ripening 
process. Few years ago it was thought that these flavoring 
substances were due entirely to the oxidation process, and 
that in order to get these flavors in butter it was necessary to 
expose the cream to pure air during the ripening. It has now 
been proved that air might be excluded from the cream-vat, 
and still good results be obtained. This does not, however, 
demonstrate that oxygen is not essential for the best results in 
cream-ripening. All cream contains more or less oxygen in 
solution. It has been thought that the oxygen that cream 
holds in solution may favor the growth of the desirable germs 
in cream, and that as soon as this has been utilized, conditions 
may become unfavorable for the desirable germs and favorable 
for the undesirable germs. 

Practically, all the investigators agree that the flavor and 
aroma substances which are characteristic of butter and which 
are developed in ripening cream, are due to bacterial growth, 
and that the germs producing lactic acid are the most desirable 
ones. We quote the followdng instances to show what effect 
some species of bacteria may have upon the quality of butter, 
when present in the cream: 



Number. 


Species Used for Starter. 


Score on Flavor, 
45 Perfect. 


Selling Price, 
per Pound. 


1 


Bacterium lactarii. 


39 
.31 


$.20 


9 


Bacillus subtillis 


.14 









These two samples of butter were made from the same 
kind of cream which was pasteurized and inoculated with 
starters from the different germs as indicated in the table.* 
The butter ripened with Bacillus suhtillis sold for 6 cents 
per pound less than the other, a difference of nearly one-third 
in value, due to the character of fermentation in the cream 
during ripening. Therefore in developing the proper flavors in 



* Bui. 40, Iowa Experiment Station. 



CREA M-RIPEXING. 



191 



butter, it is very essential that the undesirable germs be ex- 
cluded or suppressed and that the conditions for the develop- 
ment of the desirable typical acid ferments in the cream be 
made as favorable as possible. The undesirable ferments may, 
as a whole, be said to be those which act upon the nitrogenous 
matter, or those which cause ordinary decay. They very hkely 
come from filth in the barn, milking utensils, unclean milkers. 




Fig. 125. — The new Jensen cream-ripening vat. ( Peerless. j 



and unclean and dusty barns. Abnormal fermentations of 
cream, such as ropy, bitter, chromogenic fermentations, etc., 
are of course undesirable ferments. For kinds and classifica- 
tion of germs in milk, see Chapter TV on Bacteria, and Chapter V 
on Abnormal Milk. 

(2) To Increase Chumability of Cream. — Cream-ripening 
is not essential in order to complete the chm-ning process, but 
ripened cream will chum more easily and more completely than 
imripened cream, imder the same conditions. This is due to a 



192 



BUTTER-MAKING. 



lessening viscosity of the cream. The ripening process causes 
the cream to become thicker but less viscous. Undoubtedly 
the acid developed during the ripening process tends to cut 
the membrane supposed to surround the fat-globules. The 
reduced viscosity of the cream renders it easier for the globules 
to move and unite in the serum when exposed to agitation in 
the churn. It is possible to churn ripened cream in a thinner 
state and at a lower temperature than unripened cream. 

Cream which has been ripened to a normal degree of acidity, 
also allows of a more complete churning than unripened cream. 




Fig. 126. — The Boyd cream-ripening vat. 

If cream is properly ripened, and churned at a medium low 
temperature, it is possible to churn so that the buttermilk con- 
tains only about .1% of fat by the Babcock test; while if sweet 
cream is being churned under the same conditions, the butter- 
milk will contain more than this. This is undoubtedly due to 
the fact that in sweet cream the viscosity is so great that it 
prevents the minute fat-globules from uniting when agitated 
in the churn, while in sour milk the viscosity has been largely 
removed. Sour cream is thicker than ripe cream, but less 
viscous. This facilitates the coalescence of the fat-globules 
when exposed to agitation. 

(3) To Increase the Keeping Quality of Butter. — It has been 
demonstrated by several investigators that the keeping quahty 
of butter depends chiefly upon the number and kinds of germs 
present in the butter after its manufacture. In order, there- 



CREA M -RIPENING. 



193 



fore, to produce butter with good keeping qualities it becomes 
essential to exclude or suppress all germs which deteriorate 
butter. It is not of so great importance to exclude germs 
which do not injure the keeping quahty of butter. The germs 
that produce lactic acid do not cause direct deterioration 
of butter. This has been demonstrated by Jensen.* 

When cream has been properly ripened, it is practically a 




Fig. 127. — The old Jensen cream-ripening vat. 

pure culture of lactic-acid-producing germs, while sweet un- 
pasteurized cream contains a bacterial flora, consisting of a 
great many types of desirable and undesirable germs. It 
should be mentioned in connection with this, that it is only 
properly ripened cream that contains with any certainty, a 
preponderance of germs producing lactic acid. If the cream 
is over-ripe, the undesirable bacteria may also gain the ascen- 



* Landwirtschaftliches Jahrbuch der Schweiz. 



194 BUTTER-MAKING. 

dency of the desirable. When such overripened cream is 
churned, these undesirable germs are transmitted to the butter, 
and cause deterioration. If the butter is churned from properly 
ripened cream, and at the proper ripening stage, and the butter 
washed in purified water, very few undesirable germs are trans- 
mitted to the butter, and, as a consequence, it keeps better. 

Ripening Temperature of Cream. — In practice, the ripening 
temperature of cream varies within wide hmits. Some makers 
prefer to ripen cream at a temperature of about 80° F., others 
ripen at about 70° F., and still others prefer to ripen at a tem- 
perature between 60° and 70° F. Undoubtedly, the conditions 
in the creamery will to some extent govern the ripening tem- 
perature. Up to a certain limit the higher the temperature, 
the quicker the ripening process. In some instances, it is 
desirable to ripen and cool cream in a few hours, and then 
churn the same day. Under such conditions a comparatively 
high ripening temperature is undoubtedly preferable, as the 
cream will sour more quickly at such a temperature. Un- 
doubtedly good butter can be made at any of the temperatures 
mentioned above, but when we are to decide which temperature 
is the best, we are, through experimental evidence, forced to 
come to the conclusion that a ripening temperature between 
60° and 70° F. gives the best results. 

When cream is ripened at a high temperature it needs to be 
cooled very little previous to ripening. Milk is usually sepa- 
rated at a little above 80° F., and if the starter is added imme- 
diately after separation, it will ripen in a very short time. 
If ripened at a lower temperature, a longer time will be re- 
quired to develop the same amount of acid, and hence with a 
prolonged ripening period more attention is necessary. The 
Danish butter-makers ripen their cream at a comparatively 
low temperature, usually between 60° and 65° F., and obtain 
the best results. 

The germs producing lactic acid grow within a wide range 
of temperature; viz.: from about 50° to 100° F. The extreme 
temperatures are not favorable to the greatest possible growth. 



CREA M-RIPENING. 



195 



The optimum temperature, or the temperature at which they 
grow best is, according to Russell, from 90° to 95° F. At this 
temperature the germs which cause undesirable results also grow 
most rapidly in cream. Cream contains germs both of the 
desiarble and the undesirable type. At a comparatively low 
temperature (between 60° and 70° F.) the greatest relative 
growth of the desirable germs is produced. Bacteriologists also 




Fig. 128. — Cream-ripening room in the Model Creamery at the 
World's Exposition, St. Louis, Mo. 



tell us that the casein ferments as a rule thrive better at a 
lower temperature than do the lactic-acid ferments at the same 
temperature. This, keeping in mind that better results are 
obtained by ripening at lower temperatures (60° to 70° F.), 
seems to indicate that the flavoring substances are not formed 
entirely by the action of certain germs producing lactic acid, 
but that the flavoring substances are probably due to the 
joint action of several species. Lactic acid itself does not have 



196 BUTTER-MAKING. 

the desired characteristic flavor of good butter, yet we know 
that these flavoring substances are direct products, or accompani- 
ments, of the development of lactic acid. 

Cream ripened at a low temperature does not sour very 
rapidly; the germs do not grow at a very rapid rate. The 
desired degree of acidity is approached very slowly, and as a re- 
sult the fermentation may be checked almost at once when 
the desired degree of acidity has been reached, and the chance 
for getting overripened cream is reduced to its minimum. 
If the cream is ripened at a high temperature, there is greater 
danger of getting overripened cream. 

Extreme and rapid changes of temperature should be avoided 
as much as possible. The more uniform the temperature can 
be kept, if suitable for proper ripening, the better the results. 
Accordingly, the ripening-vats used in this country are practi- 
cally all jacketed, which permits the operator to regulate at 
will the temperature of the water in the jacket surrounding the 
cream. 

Amount of Starter to Add to Cream. — The amount of 
starter to add to cream will vary according to the temperature 
of the cream, and to the length of time required for ripening. 
If cream is to be ripened quickly, then a large starter should 
be added. Good results can be obtained by adding starter to 
the extent of 50% of the cream to be ripened. This much, 
however, is usually not satisfactory, as it so reduces the thick- 
ness of the cream as to render it more difficult to churn. It 
increases the amount of serum which will form the buttermilk 
when churned. The more buttermilk, the greater will be the 
loss of fat in churning. On this account it is desirable not to 
add any more starter than will give cream a proper thickness 
(from 30% to 35% fat) and at the same time supply enough 
desirable germs to gain the upper hand of, and to suppress the 
undesirable germs already present. 

It is important to skim the cream thick enough to permit 
the use of an amount of starter equal to from 8% to 20% of 
the cream to be ripened. This, under average conditions, will 



CREAM -RIPENING. 197 

produce desirable results, providing the starter is of the proper 
kind. A poor starter is worse than none at all. 

It is a good plan to pour the starter into the ripening-vat 
before the cream is separated. Some also practice skimming a 
heavy cream and then add some good morning milk to it. 

Before the starter is added all precautions possible should 
be taken in order to prevent the entrance of undesirable germs 
into the cream. The top layer of the starter should be skimmed 
off; and the very bottom portion of the starter should not be 
emptied into the cream-vat either, as it usually contains some 
of the sediments from the milk. It is essential that the starter 
should be thoroughly stirred previous to adding it to the cream, 
otherwise lumps of curd are likely to trouble during the re- 
mainder of the process of manufacture. The curd, if not 
properly enmlsified previous to adding it to the cream, is Hkely 
to show itself in the butter in the form of white specks. This 
stirring of the starter can be brought about most satisfactorily 
by pouring it back and forth from one can into another, until 
the body of the starter assumes a uniform, not lumpy, con- 
sistency. The cans used for this purpose must be carefully 
cleaned and scalded previous to using them. Dippers and 
stirrers of any kind should always be thoroughly sterilized 
previous to using them in starters. The stirrer or dipper used 
should have solid handles. This makes cleaning easier. 

Stirring of Cream During Ripening. — As soon as the starter 
has been brought into a proper condition it is added to the 
cream. If necessary it should be strained before adding. The 
cream should then be thoroughly stirred. If cream is not 
thoroughly mixed with the starter, the ripening will not be uni- 
form. If allowed to stand quietly, the cream soon separates 
into two distinct layers. The fat, by reason of its being lighter 
than the rest of the constituents, soon forces its way to the 
surface, and incorporates with it a considerable amount of 
casein. But the bottom layer will be similar to skim-milk; 
for, being better mixed with the starter, the lactic-acid fer- 
mentation proceeds more rapidly in this milky or bottom layer. 



198 BUTTER-MAKING. 

and thus prevents the fat which is at the surface from coming 
in direct contact with the flavoring substances formed at the 
bottom. If the surface layer of fat and casein were exposed 
to favorable conditions, the point might be made that the sur- 
face exposure is more desirable than if the fat were in a state 
of perfect emulsion with the rest of the constituents of cream. 
But such is not the case. The layer of fat and curdled casein, 
when allowed to form at the surface, is hkely to be contami- 
nated with putrefactive organisms. Especially is this so if 
the cream is allowed to stand in such a condition very long 
in a warm ill-ventilated room. If the constituents of cream 
are kept well mixed by stirring, the lactic acid checks the 
development of putrefactive germs, which may accumulate at 
the surface; the cream is ripened more evenly, and the flavor- 
ing substances have the best facilities of coming in contact 
with and being absorbed by the fat. 

The authors have noticed that high-scoring contest butter 
is usually made from cream which has been stirred judiciously 
at intervals. The most notable prize winners have stayed up 
with their cream all night, or part of the night, to watch the 
ripening process, and to stir the cream occasionally. It would 
not be practical to advise this method, but cream should re- 
ceive a judicious amount of stirring at intervals during the day, 
and if it is allowed to stand over night, it should be stirred 
the last thing in the evening before retiring. 

Natural and Artificial Ripening. 

Cream-ripening as a whole, as practiced to-day, may be 
divided into two groups: viz., (1) Natural, and (2) Artificial. 

Natural.— Natural cream-ripening consists in letting the 
raw cream stand at a certain temperature until it is sour, then 
cooling it to the churning temperature. This method used to 
be practiced nearly altogether, but now experimental and 
practical evidence prove that this is not the method by which 
the best butter can be produced. Natural ripening may, or 



CREAM-RIPENING. 199 

may not, produce good results. It has been termed by some 
"chance ripening/' At certain seasons of the year conditions 
are favorable for natural ripening, while at other seasons con- 
ditions are very unfavorable. It was stated before that putre- 
factive organisms, or those germs causing ordinary decay, are 
undesirable species of bacteria to have present in the cream. 
During the late spring and early summer months, when the 
cows are first put on pasture, the conditions are favorable for 
the preponderance of the desirable germs; during the winter, 
when necessarily the cows and the milk are subject to stable 
conditions to a greater extent, the conditions are favorable for 
the ascendency of the undesirable germs. Eckles has found 
that during the winter about three-fourths of the bacteria in 
milk consists of these undesirable germs. If these are present 
in the milk, a proportionate part will be transferred to the 
cream. When such cream is allowed to ripen or ferment in a 
natural way, the undesirable germs are likely to gain the ascen- 
dency. As the conditions which govern the degree of con- 
tamination of the milk and cream vary during the different 
days of the different months and different seasons of the year, 
this natural ripening is not to be depended on for obtaining 
a good uniform quahty of butter, even though at times good 
results may be obtained from natural ripening. A maker who 
wishes to make a high, uniform grade of butter should not 
depend upon natural cream-ripening. 

Artificial Ripening. — By artificial ripening we mean (1) 
ripening of raw cream to which sufficient starter has been 
added to control the kind of fermentation; (2) ripening of cream 
in which the germs have been destroyed by pasteurization, 
and to which a starter has been added in order to introduce 
the desirable ferments. 

(1) Either of these methods is preferable to natural cream- 
ripening. The first method has been the most common in the 
past, but the latter method promises to give results which 
will warrant every butter-maker in adopting it as a permanent 
method in butter-making. If cream has been handled under 



200 BUTTER-MAKING. 

conditions which are favorable for the introduction of desirable 
germs, and is otherwise in good condition, the best results can 
be obtained by ripening such cream without pasteurizing it. 
It is asserted that when all conditions are ideal, — the starter 
good, and the cream good, — then a higher flavored butter can 
be produced by this method than if the cream were pasteurized; 
but the keeping quality of the butter is not so good as that 
produced from pasteurized cream. The same objection that 
was made to natural ripening can be made to the artificial 
ripening of raw cream. If the butter-maker at the creamery 
has full control of all the conditions governing the quahty of 
butter, and if the milk is received at the creamery in an ideal 
condition, then this method of ripening is commendable. But 
at creameries where milk is at times delivered from one hundred 
or more different patrons, some of the milk is likely to come 
in in an unfavorable condition. The poor milk is likely to 
contaminate all the remainder of the cream, and objectionable 
fermentative products are likely to develop in the cream-vat. 

When this method of ripening is practiced the starter should 
be added to the cream as soon as possible. In fact, this rule 
applies to all methods of cream-ripening where a starter is used. 
It is preferable to add the starter to the cream-vat before the 
skimming is begun. In this way the lactic-acid germs in the 
starter get a chance to work in the cream immediately after 
it is skimmed, and, for this reason, are more Ukely to suppress 
the undesirable types of ferments present. 

2. The second method, that of pasteurization, is without 
any question the ideal way of manufacturing butter. It has 
been advocated in a theoretical way for several years in this 
country, but only within recent years has this method of 
ripening cream been deemed sufficiently meritorious to warrant 
its adoption. It is, however, rapidly gaining in favor. The 
method consists in heating the cream on a continuous pastuerizer 
from 155° to 190° F. A temperature of about 180° F. is the 
one usually employed. It is said that a temperature of 140° 
to 150° F. destroys practically all the germs producing lactic 



CREAM-RIPEXING. 201 

acid. Some undesirable germs also, in a vegetative stage, are 
not destroyed at this temperature. For this reason cream 
should be heated to about 180° F. At this temperature, the 
germs causing tuberculosis are destroyed. It is in order to com- 
bat tliis disease that the Danish Government compels all cream 
to be pasteurized before it is made into butter, and also all of 
the skim-milk before it is returned to the farmer. The germs 
causing tuberculosis are destroyed at a lower temperature than 
this (180° F.), provided they are exposed to the temperature for 
some time. In creameries the intermittent method of pasteur- 
ization is used. In this method the time of exposure to the heat 
is short, and consequent^ a higher temperature is necessary. 

By heating milk to such a temperature practically all of the 
germs, desirable and undesirable, are destroyed with the ex- 
ception of those that are present in the spore form. If tliis 
cream is inoculated with the desirable germs, then theoretically 
and practically, good imiform results should be obtained. 

It was mentioned above that the spore-bearing bacteria were 
not destroyed by the degree of heating to which cream is ex- 
posed. If the cream is allowed to stand any length of time at 
a favorable temperature \\ithout a starter in it, these spores 
wiU develop and cause imdesirable results. If pasteurized 
cream is allowed to ripen naturally, a very bitter flavor usually 
develops. In order to overcome this undesirable fermentation, 
it is essential that the starter should be added as soon as possible 
after the cream has been cooled down to the desirable ripening 
temperature. It should be remembered that tliis starter should 
never be added to the cream while it is still hot, as the lactic- 
acid producing germs in the starter would then be destroyed. 

Ripening Cream When Churning is Done Once Every Other 
Day. — At certain seasons of the year the milk delivered to the 
creamery is not sufficient in quantity to produce enough cream 
so that it is worth while to churn every day. Many makers 
profitably utilize their time by churning only every other day. 
The question then comes, how may the cream be preserved, in 
the best possible condition? Some prefer to cool the cream to 



202 BUTTER-MAKING. 

a low temperature (50° F.) immediately after it has been 
skimmed or received, then allowing it to stand until the next 
day. The second day's cream is then poured in with the first 
day's cream, the starter added, and the ripening process com- 
pleted. Others prefer to add the starter to the first batch of 
cream immediately after it has been skimmed, then ripen it 
almost to the normal degree of acidity, and cool to about 50° F. 
The next day the new cream is skimmed into this already 
ripe cream, stirred thoroughly, and the ripening process com- 
pleted. The latter method, if done properly, has given the best 
satisfaction. When cream is ripened according to the method 
first described, undesirable fermentations are likely to gain 
ascendency. As has been mentioned before, the undesirable 
germs grow better at a lower temperature than do the bacteria 
producing lactic acid. When the next day's cream is skimmed 
into this, the undesirable ferments may preponderate to such 
an extent that the desirable germs cannot overcome or suppress 
them during the remainder of the ripening process. According 
to the latter method, the first day's cream is ripened as usual. 
When the next day's cream is skimmed into this, the first lot 
of cream acts as a starter. The lactic acid present inhibits 
the growth of other undesirable species, and consequently 
better results are obtained by this method. 

This latter method of holding cream is recommended when 
cream is to be held for any length of time, such as over Sunday, 
or when the creamery is run only every other day, and the 
churning done once or twice per week. If possible, and all 
the other conditions consistent, it is better to ripen the cream 
and churn it the day it is dehvered than it is to hold the cream 
over for several days before it is churned. Butter will always 
keep better than cream, under any conditions. 

Mixing of Cream. 

With the introduction of hand-separators the quality of 
cream received at creameries varies considerably. The ques- 
tion then arises, should the different quantities of cream be 



CREAM-RIPENING. 203 

mixed, or should they be treated separately according to 
quality, and made up into several grades of butter? Theoret- 
ically the grading of cream into two or three, or even four, 
grades can be argued to be correct and proper, yet in creameries 
where only a comparatively small amount of cream is handled, 
it usually does not pay to grade very much. In a very large 
plant where as much as 50,000 pounds of butter is made per 
day, there is no question that a system of grading cream pays. 
Several large central plants are now grading their cream into 
three or four grades successfully. In smaller plants, however, 
it is not as a rule advisable to make more than two grades, 
the first grade to include all good and fair cream, and the 
second grade to include the very poorest. Usually in the 
comparatively small creamery plants, the ciuality of cream can 
be better controlled, and consec^uently less grading is necessary, 
while in a large plant the creamery manager has but little con- 
trol over the conditions governing the quality of the cream. 

The chief conditions that determine whether different 
qualities of cream should be mixed, might be said to depend 
upon: 

(1) The quahty of the cream. 

(2) The kind of market for the butter. 

(3) The amoimt of hand-separator cream compared with 

the amount of good quality cream, usually sepa- 
rated from the milk at the creamery. 

(4) The general creamery conditions. 

I. Quality of Cream. — The difficulty of grading cream is met 
with chiefly in comparatively small creameries where part of 
the intake is cream and another part milk. The cream that 
is separated from the milk at the factory is usually in an ex- 
cellent condition, while the cream delivered from hand sepa- 
rators, or raised by any of the gravity methods, is usually of a 
poor quahty. If the cream delivered to the creamery is in 
just as good condition as that obtained from whole milk skimmed 
at the factory, then there is no danger in mixing the two kinds 



204 BUTTER-MAKING. 

of cream. If it comes in a poor condition, such as hand- 
separator cream usually does, then the poorest cream should 
be ripened by itself. Some maintain that the mixing of the 
two kinds of cream is favorable, because, if the hand-separator 
cream were churned separately, it would produce butter wliich 
is very poor in quality, while, on the other hand, if the two 
were mixed a better quaUty as a whole would be obtained. 
This is undoubtedly true; but evidently if the quality of 
butter from the hand-separator cream was raised, that from 
the whole milk was lowered, so that the quaUty of butter re- 
cei^'ed from both was poorer than that which would have been 
obtained from the whole milk if kept separate. 

2. Kind of Market. — If a creamery operator is worldng 
strictly for quality, and the butter is sold on that basis, it 
certainly would not be a good plan to mix the poor cream 
with the better cream. On the other hand, if the butter is 
sold on the market with no attempt to estabhsh a reputation, 
no further aim than to get as much as possible out of the present 
supply, then it might pay. By mixing the two it might be 
possible to raise the quahty so as to bring all of it on the market 
at a trifle above "Creamery Extras ""; while if the cream from 
the whole inilk were kept separate, perhaps no greater price 
could be obtained for the butter produced from tliis better 
cream. If the butter from the poor hand-separator cream 
were placed on the market by itself, evidently it would not 
command the same price as that made from the whole milk, 
or the mixed lot either. As has been stated before, the mixing 
of poor cream with a good quahty of milk, skim-milk, or whole 
milk, and stirring the mixture thoroughly improves the quality 
of the butter in a marked degree. 

3. Amount of Cream. — If only a small amount of hand- 
separator cream is being received, then usually it will not pay 
to earr}- it through by itself. By experience the authors have 
found that the best way to dispose of a comparatively small 
amount, pro^iding it is not too soiu. is to empty it into a 
recei vino;- vat \\\xh. the milk, and stir it well, re-skim it and 



CREAM-RIPEXIXG. 205 

pasteurize all the cream, add a starter, and ripen in the usiia 
way. If the cream is sour, and there is a danger of souring 
the remainder of the milk, or clogging the separator, it is ad- 
visable to add it directly to the cream- vat. The sourness of 
the cream is not so dangerous if the flavor is clean. If it is 
very unclean, and not sour, the mixing with the whole milk. 
the separation, and pasteurization will eliminate a great many 
of the imdesirable flavors and check the acti^-ity of a large 
portion of the undesirable germs present. AAlien the starter 
is again added and ripened, a good c^uahty of butter is ob- 
tained. If a comparatively large amomit of cream in poor 
condition is received, then it is advisable to retain it by itself. 

4. General Creamery Conditions. — OccasionaUy it happens 
that a creamery is not properly equipped with vats, so as to 
enable an operator to handle two lots of cream. "^Miere one 
man has to do aU the work, one churning is about all he can 
accomplish daily, besides attending to the remainder of the 
work. I'nder such conditions it is doubtful whether it Vvill 
pay to purchase additional vats and Mre adcUtional help, in 
order to keep poor hand-separator cream separate from the 
remainder, through the chfferent steps of manufacture. Since 
the butter is not sold strictly on its merits, there would, as a 
rule, be no profit for the average small creamery to grade the 
cream, on account of the additional labor and apparatus re- 
quired. If a liigh quahty of butter is the supreme aim of the 
creamer}' operator, then it becomes very essential that the poor 
cream be kept separate. 

Exa:mixixCt axd Testixg Crea:\i for Acidity DmixG 

RiPEXIXG. 

As has been stated before, the best flavor in butter is pro- 
duced when cream is ripened to the proper degree of acidity. 
If it is ripened too much, or overripened, the butter vnJl assume 
a liigh flavor and strong aroma, while if not ripened liigh enough. 
it will be a httle fiattish ^ith less aroma. Many makers depend 



206 



BUTTER-MAKING. 



upon the taste and smell, and the appearance of the cream, 
to decide when the cream has been ripened to the desired 
degree of acidity. Makers with a great deal of experience are 
able to tell quite accurately by the appearance of the cream 
and its taste and smell when it has been properly ripened. 
Well-ripened cream gets an apparently granular and glistening 
condition. It has a pleasant, mild acid taste, and a good 
clean sourish aroma. 

As the flavor of properly ripened cream will vary somewhat 
according to the different degrees of richness of the cream, it 
is very easy to be deceived by the 
senses. For this reason it is advisable 
to use a special test with which to 
measure the amount of acid developed 
in the cream. There are two acid tests 
in general use now in creameries, viz., 
"Mann's Test" and the "Farrington 
Test." 

Mann's Test. — Mann's test consists 
of measuring the acid in the cream 
I by means of an alkali of a definite 
known strength. The kind of alkali 
used is usually a .1 normal solution of 
caustic potash (KOH) or soda (Na.OH). 
^ Mann'-^ddTsl!"' In- These solutions can be made up very 

stead of the burette the cheaply or bought from the supply- 
alkali can be kept in a , ,, ? , , • i i 

large bottle, as shown in houses. Mann s test IS based upon mea- 
Fig. 131 and 130. suring out 50 c.c. of cream by means 

of a pipette. A few drops of an indicator (phenolphthalein) 
is. added. This indicator gives a red color in an alkahne solu- 
tion, and no color in an acid solution. The .1 normal alkali 
is poured into a burette, and the solution allowed to run into 
the 50 c.c. of cream and stirred thoroughly until it begins to 
turn pink in color. At this point it is neutral. The number 
of cubic centimeters of alkali required to neutrahze the acid 
in 50 c.c. of cream indicates the number of degrees of acid. 




CREAM-RIPENINO. 



207 



For instance, if it required 32 c.c. of a tenth normal alkali 
to neutralize the acid in 50 c.c. of cream, the acidity of the 
cream would be 32°. 

(1 c.c. of N/10 alkah= 1° Mann's Test.) 

Mann's test reading can be converted so as to express the 
results in percentage similar to the Farrington test. As 1 c.c^ 




Fig. 130. — Arrangement 
for keeping alkali for 
the Mann's test. 



Fio. 131. 



of the .1 normal alkah neutraUzes .009 grams of pure lactic 
acid, 32 c.c, as in the above case, would neutrahze32 times .009. 
This would give the amount of acid, calculated in terms of 
lactic acid, present in the 50 c.c. of cream. This product 



208 



BUTTER-MAKING. 



divided by the 50, and multiplied by 100, would give the per- 
centage of the acid present. 

Farrington Test. — The same principle is involved in the 
Farrington test. The alkali is put up in small tablets, already 
containing the indicator. These tablets contain a definite 
amount of alkah, and are represented as retaining their strength. 
However, they lose their strength if they are exposed to the 
atmosphere. The amount of alkali embodied in each tablet is 
such that when five of them are taken into a graduated cylin- 
der, the cylinder filled up with distilled water to the 97-c.c, 



111 Iff 




Fig. 132. — Apparatus for the Farrington acid test. 

mark, and the tablets thoroughly dissolved in water, a solution 
is obtained, each cubic centimeter of w^hich represents .01 of 
1% of acid, providing 17.6 c.c. of cream is taken. The tablets 
can be made up of different strengths for the use of different- 
sized pipettes, but as the 17.6-c.c. pipette is the one which is 
used in the ordinary Babcock test, directions are given for the 
use of that pipette only. For a more detailed description of 
the acid tests see "Milk Testing," by Farrington and Woll. 

Amount of Acid to Develop. — The amount of acid to develop 
in cream depends upon the amount of fat present in the cream, 
and to some extent upon the market on which the butter is 



CREAM-RIPENING. 209 

to be sold. Some markets require higher flavored butter than 
others. Practically all markets, especially in this country, 
demand butter which has a comparatively rich creamy flavor, 
with a nice clean butter aroma. 

It was found by the Iowa Experiment Station, from a large 
number of experiments, that cream containing 30% fat should 
be ripened to 37° Mann's test, in order to get the very best 
results. It has also been demonstrated, that the acid is developed 
only in the serum portion of the cream. From this it can be 
seen that the more fat there is in the cream, the less serum there 
will be. As the acid develops only in the serum, the less acid 
it will be necessary to develop in rich cream in order to have 
a definite strength of acid in the serum portion. On the other 
hand, the less fat there is in the cream, the more serum there 
wdn be, and the more acid necessary compared with the whole 
amount of cream, in order to get the same strength of acid 
in the serum part. 

A definite relation of fat to the amount of acidity produced 
can be obtained by making use of the following f ornmla : 

Subtract the per cent of fat found in the cream from 100, 
and the remainder will be the serum. Divide this by two, and 
the quotient represents the number of degrees of acidity (Mann's 
test) required. For instance, if we were to ripen a vat of 
cream containing 32% fat, the problem would stand something 
like the following: 

100 -32 = 68 -^2-34° acidity, to be developed in that partic- 
xQar vat of cream to obtain the best results. 

/lOO- fat in cream , ,. • ,• • i\ 

I = degrees ot acidity required. I 

The above formula will give good results when normal 
cream is being ripened. When the cream gets abnormally thin, 
the result will be a little too high, and when very rich cream 
is ripened, the result will be a little too low. It is usually 
said that it is not advisable to ripen cream any higher than 
to .65% of acidity. 



210 BUTTER-MAKING. 



Chemical, Physical, and Biological Changes. 

Physical Changes. — All the changes in cream during ripening 
are very complex, and the causes of them are not well under- 
stood. The chief cause of the ripening process, as it normally 
occurs, is the action of micro-organisms. As has been stated 
before, the germs producing lactic acid are the most numerous. 
These germs continue to gain the ascendency in the cream 
during the ripening until cream is almost a pure culture of 
lactic-acid-producing germs. Accompanying this growth, the 
sugar present in the cream is broken up into lactic acid and 
several other by-products which will be mentioned later. 

These different by-products have certain physical effects 
upon the body of the cream. The acid developed causes 
the cream to coagulate and become thick. As the ripening 
process is carried on the appearance of the cream changes some- 
what. It becomes thick, granular, and glistening in appear- 
ance. Undoubtedly the film of casein, or whatever the envelop- 
ment may be, surrounding the fat-globules, is loosened or cut. 

Biological Changes. — Cream when put into the ripening-vat 
usually contains a very large variety of bacteria. Wliich 
species predominates at that time depends upon the care and 
treatment of the cream previous to the ripening stage. In 
pasteurized cream practically all the germs present are of the 
spore-producing kind, and unless conditions are favorable for 
the development of the spores, these will be suppressed by the 
germs added with the starter. During the first few hours of 
the ripening process there is a gradual growth of all the germs 
present. It is said that in sweet cream the lactic acid germs 
are comparatively few in number, but under favorable conditions 
these grow so much more rapidly in number than any of the 
others, that in a short time they become more numerous than 
all the other germs. The by-product lactic acid is unfavorable 
for the growth of nearly all the undesirable varieties of germs. 
Practically all these germs are suppressed in their development^ 



CREAM-RIPENING 



211 



SO that when cream is ripened properly, it contains few other 
germs besides those which produce lactic acid. 

From the above it will be seen that there are practically two 
overlapping periods in the bacterial changes during the ripening 
of the cream, and especially is this so in the ripening of raw 
cream. The first includes the period when all the different 
varieties of germs grow, and the second includes the period 
when only the lactic-acid- producing germs grow. It is, there- 
fore, maintained that before the churning takes place the 
ripening of cream should be carried on to such an extent that 
the lactic-acid germs only predominate. Dr. Storch, who has 
made a detailed study of this, asserts that milk and cream 
both have a rather undesirable flavor at the beginning of its 
ripening period, while in the latter stage of the ripening period 
it takes on a pleasant, clean, acid taste. 

The number of germs, and the relative number of acid-pro- 
ducing germs in the cream when ripened, is as shown in the 
following table : * 



Date. 


Quality of 
Cream. 


Number per c.c. 


Number Acid 
per c.c. 


Per 

Cent 
Acid. 


Number Non- 
acid per c.c. 


Per 
Cent 

Non- 
acid. 


Feb. 11 
Jul. 18 


Fine 

Poor 

Excellent 

Good 

Fair 

Good 


280,000,000 


257,000,000 


92 


22,400,000 


8 
19 


" 30 

Aug. 11 

Sep. 3 

5 

Oct. 28 

" 30 


3,002.000,000 
1,107,000,000 
1,027,000,000 
2,007.958,000 
392,958,000 
393,700,000 


2,851.190,000 

1,012,072.200 

955,110,000 

1,827,370,000 

385,098,840 

381,889,000 


95 

91.5 
93 
91 

98 
97 


150,810,000 
94,928,800 
71,890.000 

180,588,000 

7,859,160 

11,811,000 


5 

8.5 

7 

9 

2 

3 



Eckles found that when good- flavored cream is ready for 
churning the number of bacteria per cubic centimeter varies 
from 380,000,000 to 3,000,000,000. Of this number the acid- 
producing bacteria constitute from 91% to 98%. 

Chemical Changes. — The changes in cream during the process 



* Bui. 40, Iowa Experiment Station. 



212 BUTTER-MAKING. 

of ripening are not due to any instability of the components 
of cream, nor are they attributed to any of the enzymes. 
Galactase is a pre-existing enzyme in milk; consequently it 
would be present in cream, but present only to a very small 
extent. If it were possible to exclude from the cream all the 
different kinds of bacteria, ripening would not take place. 
At least it would proceed at a much slower rate than the 
ordinary rate of change in the ripening of cream ; this proves 
that the soHds of cream are chemically stable and that the 
enzymes or unorganized ferments play only a secondary part 
in bringing about the different changes in cream ripening. 
There are two classes of solids in cream which are decom- 
posed chiefly during ripening: viz., (1) Albuminoids, and (2) 
Sugar. 

1. Most authorities maintain that bacteria are unable to 
feed on, or to decompose directly any substance which is not 
present in the form of a solution. As casein is not normally 
present in a solution in milk, the pre-existing enzymes or 
bacterial by-products must cause the first decomposition of 
casein before the germs are able to utilize it. The by-products 
resulting from the casein ferments are many, and very com- 
plex. According to Russell * albumoses, leucin, peptone, 
tyrosin, and ammonia are formed. Freudenrich claims that in 
addition to these butyric acid is a by-product. Besides these 
substances, gases such as carbonic gas, marsh-gas, and nitrogen 
are formed. Whether all these by-products are formed directly 
or indirectly or both, no one knows for certain. 

The typical ferments seem to act similarly upon the casein 
in milk. They produce first a rennet-like ferment, which 
curdles the milk. After it has been curdled, the curd is digested 
or peptonized by the action of some enzyme. The casein in a. 
sample of milk containing a preponderance of casein ferments 
will in a few weeks, or even less time, disappear entirely. Ap- 
parently the milk has been transformed into whey. This 
particular ferment is called casease by Duclaux. Conn calls 

* Dairy Bacteriology. 



CREAM-RIPENING. 213 

it a tryptic ferment, because it is similar in its action to the 
trypsin produced by the digesting glands. The putrefactive 
germs ordinarily act upon the nitrogenous matter of cream, 
as described above. 

2. The milk-sugar in cream is present in a perfect solution, 
and consequently it is thought that bacteria are able to utilize 
it as food directly. The typical lactic-acid-producing germs 
cause the milk-sugar to split up into lactic acid chiefly, accord- 
ing to the following equation: 

C12H22O11 -|-H20 = 4C3H603. 
Milk-sugar. Lactic acid. 

There are a number of germs which are able to produce 
lactic acid from milk-sugar, but practically all of them, so far 
as known, produce other by-products besides the lactic acid. 
Some germs produce much lactic acid and a small amount of 
other by-products, while other germs produce little lactic acid 
and large amounts of several other by-products. Some of them 
break up the milk-sugar and change it into lactic acid and car- 
bonic gas. Other species produce lactic acid and alcohol. 
This latter species Grottenfelt claims to be closely associated 
with the production of flavoring substances in butter. Different 
kinds of gases, such as nitrogen, hydrogen, carbonic- acid gas^ 
and marsh-gas are also formed. 

It is doubtful whether there are any germs which are able 
to transform milk-sugar entirely into lactic acid. If such were 
the case, 1 gram of milk-sugar would produce 1 gram of lactic 
acid. According * to some experiments carried on by one of 
the authors, .8 of a gram was the maximum amount of acid 
developed from 1 gram of milk-sugar, and .5% is the average 
amount of acid developed from 1 gram of milk-sugar. In the 
experiments, efforts were made to have the typical lactic-acid 
ferments present in the cream. The following table may prove 
of some interest: 

* Chemical Changes during Cream Ripening. (Thesis I. S. C.) 



Per Cent of 
Acid in Cream. 



214 BUTTER-MAKING. 

Cream I. 

Sugar. Acid. 

1st ripening period 1% produced -04% .33% 

2d " " 1 " .06 .35 

Cream II. 

1st ripening period 1% produced .08% .58% 

2d " " 1 " .06 .64 

3d " " 1 " .045 .82 

Cream III. 

1st ripening period 1% produced .051% -58% 

2d " " 1 " .050 .63 

3d " " 1 " .016 .68 

Average of S.experiments 1 " .05 + 

Conn states that the lactic acid produced in cream during 
ripening is not always of the same kind. Some species of 
bacteria produce the kind which turns the plane of polarization 
to the left; other species produce the kind wliich turn it to 
the right, and still other species produce the so-called inactive 
lactic acid. The most common are those wliich produce acid 
that turns the plane of polarization to the right. 

The souring of cream, according to Conn, is not due to the 
development of lactic acid alone. Two kinds are produced, 
(1) fixed, and (2) volatile. The fixed acids appear to be chiefly, 
if not wholly, lactic acid, and the volatile are chiefly acetic and 
formic acids. The fixed acids are produced in the greatest 
proportion. 

In the table quoted above, it wifl be seen that during the 
first ripening period of sample 3, .1% sugar produced .051% of 
acid, while during the last or third ripening stage .1% of sugar 
produced .016% of acid, being only about one- third of that 
produced during the first ripening period. The same is true 
in experiment II, where three separate analyses were made of 
the cream. It is difficult to account for the constant decrease 
of lactic acid in proportion to the sugar decomposed in the 
advanced stage of the ripening period. Is it the lactic acid 
already present that decomposes into other products when so 
much acid is formed? Or do the bacteria continue to decom- 
pose the sugar, but the by-products being of a different nature? 



CREAM-RIPENING. 215 

Or do certain species of bacteria cease to act, and are other 
species, which produce less lactic acid and more gaseous prod- 
ucts, able to perpetuate their growth and bring about the 
results observed? The results are probably due to a com- 
bination of the different actions just mentioned, but the most 
likely theory is that conditions for the growth of other species 
of bacteria become more favorable, and other by-products 
than lactic acid are formed, products that cause the undesirable 
rancid flavors in over-ripened cream. 

Butyric acid also results from the decomposition of cream 
constituents during ripening. The origin of the butyric acid 
formed during ripening is, however, not well known. Freuden- 
reich says it is the residue resulting from the breaking down of 
casein and milk-sugar in various ways, and therefore he classes 
the butyric ferments in the same group as the casein ferments. 

Butyric acid in overripened cream is by some authorities 
considered to be a direct product from an excessive amount of 
lactic acid. Each molecule of lactic acid breaks up into butyric 
acid, carbonic-acid gas, and hydrogen, according to the follow- 
ing equation: • 

Lactic acid. Butyric acid. • , „.„„ " Hydrogen. 

2C3H6O3 = C3H7CO2H + 2CO2 + H4. 

It is questionable whether this reaction ever occurs in the 
ripening of cream. 

Butyric acid also results from the decomposition, of butyrin, 
through the action of bacteria, and causes the molecules of fat 
to spht up into butyric acid and glycerine, according to the 
following equation : 

Butyrin (fat). Water. Glycerine. Butyric acid. 

fCsHyCOa fOH 

C3H5 j C3H7CO2 + 3H2O = C3H5 { OH + 3C3H7CO2H 
[ C3H7CO2 I OH 



CHAPTER XV. 

STARTERS. 

Definition. — By the term starter, in cream-ripening, we 
understand a medium containing a preponderance of desirable 
germs present in a virulent condition. 

History. — The use of starters in the dairy industry dates 
back a great many years. The fact that starters helped in the 
manufacture of dairy products was recognized years ago by 
practical men even before scientists recommended the use of 
pure cultures. In European dairy countries the use of the 
buttermilk borrowed from a neighboring factory to add to the 
cream in order to overcome abnormal conditions, was a common 
occurrence. In Holland, sour whey borrowed from some other 
factory was used to overcome gassy fermentation in cheese- 
making. While the reasons for this were not well understood, 
the underlying principle was involved, viz., that of overcoming 
the undesirable fermentation by adding ferments of an an- 
tagonistic kind. 

The introduction of pure cultures, or commercial starters, 
for cream-ripening dates back to 1890, by Professor Storch. 
He recommended their use in creameries in Denmark. Starters 
were used in that country for a time successfully, and since 
then starters have been introduced and extensively used in 
this country, as well as in practically all European countries. 

Classification of Starters. — Generally speaking, the different 
kinds of starters are included under the names (1) Natural, 
and (2) Commercial. The latter is prepared from a pure 
culture of bacteria obtained from the laboratory. The former, 
or natural, include a great many kinds of dairy products which 

216 



STARTERS. 217 

are supposed to contain a preponderance of those germs which 
are involved in the production of desirable flavors in butter. 
Buttermilk, sour cream, whey, and sour whole or skim-milk, 
are classed under this heading. While all these may be termed 
natural starters, and at certain times the use of any one of 
them may produce better results than if no starter at all were 
used, it is not safe to rely upon these to bring about better 
results than could be obtained without the use of starters, 
because these products are likely to be contaminated in a large 
degree with undesirable germs. 

Preparation of Natural Starters. — The best natural starter 
is usually obtained by selecting a number of different samples 
of the best milk coming into the creamery, into cleaned sterile 
glass jars. The samples are allowed to stand until sour at 
about 70° F. The sample which coagulates into a smooth uni- 
form curd, and has a pleasant acid taste and smell is selected 
and used as a mother-starter. When inoculated into a large 
quantity of selected pasteurized skim-milk, cooled to and kept 
at a temperature of about 70° F. until it begins to coagulate, 
it will usually produce a starter which is equal, and often 
superior, to a commercial starter. 

Commercial Starters, or Pure Cultures. — Experiments have 
amply proved that certain species of bacteria are chiefly re- 
sponsible for the butter flavors developed in cream during 
ripening. This fact has given rise to the use of pure cultures 
prepared in a commercial way. These pure cultures contain, 
in a virulent condition, the germs which produce the desirable 
flavors and aroma. The cultures are put up in laboratories 
specially provided for this kind of work. The germs are iso- 
lated and inoculated into a medium which is suitable to their 
growth. Some laboratories inoculate them into a liquid medium, 
others into a powder medium. The hquid medium consists 
usually of sterilized bouillon, or milk. The powder medium 
consists chiefly of milk-sugar. The cultures that are put up 
in the liquid form will not keep so long, and it is not safe to use 
them after they are about nine days old. The cultures which 



218 



BUTTER-MAKING. 



are put up in powder form have the advantage that they can 
be kept for a much longer time and stih retain their vitahty. 
Both kinds as a rule are good while they are fresh. We give 
below a list of the conmiercial cultures with which the authors 
are familiar: 



Commer- 
cial 
Starters 



Ameri- 
can 



S. C. Keith, 
Charlestown, 

Mass. 

O. Douglas, 
Boston, 

Mass. 

Eloc Ericsson, 
St. Paul, 
Minn. 

Hansen's, 
Little Falls, 
N. Y. 



1 Lactic Acid Culture. 1 

!■ Duplex Culture \ Liquid. 

J Boston Butter Culture J 

1 Boston Butter Culture ] 

!- Duplex Culture j' Liquid. 

J Lactic Acid Culture J 



' Ericsson's Butter Cul- 
ture 



Liquid. 



1 



Lactic Ferinent 



Powder. 



Foreign 



Park Davis & Co., ] 
Detroit, 
Mich. 

Conn's Culture, 
Storr Station, 
Conn. 

Blauenfeldt & 
Tvede, Copen- 
hagen, Den. J 

Hjort & Fog's 1 
Lab'tory Cul 
Copenhagen, 
Den. 



Flavorone 



f This culture is put up 
•| in tablet and cap- 
[_ sule forms. 



Bacillus 41 



Danish Lactic Acid 
Ferment 



Liquid. 



Powder. 



\ Lactic. 



S. P. Storm, 
Tillitze, Naks- 
kov. Den. 



1 



Starter. 



Preparation of Commercial Starters. — x-Vll of the starters 
mentioned above have been tested and are known to produce 
good results. The first step in the preparation of a mother- 
starter (starterline) is to prepare preferably a glass jar or 
bottle by thoroughly cleaning and sterihzing it. Glass jars are 
used in preference to any other vessel, because if they are un- 
clean in any way, it will show through the glass. Secondly, 
there are no seams and no places on the inside which will cor- 



STARTERS. 219 

rode, and in that way retain unnoticeable dirt. Mason jars 
and sampling bottles are suitable. The kind of bottle wliich 
is used for marketing milk gives very good results. 

The second step consists in selecting suitable milk. The 
milk must be in as pure and sweet a condition as possible. A 
good starter can be produced from either whole or skim-milk. 
Skim-milk, however, is preferable to whole milk. The mis- 
take of selecting whole milk for starters has often been made. 
The mother-starter prepared from whole milk usually has a 
more pleasant, mild, rich taste, due to the fact that it contains 
more fat than the starter made from skim-milk. The mother 
starter prepared from good skim-milk is preferable, and safer 
to rely upon. Efforts should be made towards separating the 
starter milk before the rest of the milk has been run through. 
If not separated till late during the run of the day, the separator 
is filled with slime and bowl-slush, which are likely to con- 
taminate the starter milk. At some creameries, the separation 
of the starter milk is accomphshed with a small hand sepa- 
rator. This, however, is not convenient or practicable at most 
creameries. The milk for the starter can be selected and run 
through the power separator during the beginning of the run. 
It is well not to use the very first milk which passes through 
the separator, as it would be likely to contain a greater number 
of undesirable germs. 

The milk which has been selected for the mother-starter, 
or starterline, is then pasteurized. The pasteurization is best 
accomphshed by the intermittent method. If considerable 
milk is to be pasteurized it is best to make use of a clean, 
sterihzed can. If only a small portion is to be pasteurized, 
just enough for the mother-starter, the milk can be put di- 
rectly into the jars. The jar half full is about the proper amount 
of milk to use. The directions sent with some pure cultures 
recommend as much as half a gallon or a whole gallon of milk. 
As a rule better results are obtained if only about a pint of 
milk is taken. If the milk for the mother-starter is pasteurized 
in the glass bottles or jars, then it is advisable to set the bottles 



220 BUTTER-MAKING. 

containing the milk into cold water, — covering the jar so as 
to prevent outside contamination, — and then heat up the 
water gradually. Care should be taken not to insert these 
bottles suddenly into scalding hot water, or to let the steam 
strike them, for either is likely to crack the bottles. Care 
should be taken also to exclude water from milk used for 
starters. It is advisable to heat this milk, for the starterHne, 
as liigh as possible in scalding water, say up to about 200° F. 
The sample may assume a cooked taste, but this will soon 
disappear after the starter has been carried on a few days. 
The milk should be left at this high temperature for about ten 
or fifteen minutes. A longer time does no harm. Then the 
milk is gradually cooled to about 80° F. This high temperature 
is desirable, because the germs present in the commercial cul- 
ture may be somewhat dormant. This high temperature would 
tend to revive them more quickly than a lower temperature. 
Great care should always be taken to cool the milk previous to 
inoculating it with the pure culture, otherwise the germs present 
in the pure culture will be destroyed. 

Inoculation.. — The next step is to inoculate the prepared 
milk with the pure culture obtained from the laboratory. The 
bottle which contains the pure culture is carefully opened, then 
the bottle containing the culture is turned over and emptied 
into the pasteurized milk. The bottle should be held down 
closely to the mouth of the jar containing the sterile milk, in 
order to prevent too much contamination from the air. Then 
the milk containing the pure culture is thoroughly stirred and 
set away in a room where the temperature is about 70° F. 
Tliis will gradually cool the milk from 80° to 70° F., and in 
about twenty to forty hours the milk will sour and coagulate. 
Germs in nearly all of the liquid cultures are rather slow in 
acting upon the milk, undoubtedly due to the dormancy of the 
germs, and to a comparatively few of them being present in 
the pure culture. When the powdered cultures are used, a 
little more care is essential to get the powder thoroughly min- 
gled with the milk. It is a trifle more difi&cult to get the 



STARTERS. 221 

powder thoroughly mixed with the milk than it is to get the 
liquid cultures mixed. If anything is used with which to stir 
the sample, it should be sterilized before coming in contact 
with the milk. This applies in the preparation of all cultures. 
In testing or samphng the mother-starters, nothing should be 
allowed to come in contact with it unless it has previously been 
thoroughly sterilized. The powder cultures are usually more 
vigorous in their effect than most of the liquid cultures now 
on the market. The powder cultures usually coagulate the 
sample in about twenty-four hours, and if the operator is used 
to handhng the liquid cultures, he should watch the mother- 
starters prepared from powder cultures, so that they do not 
get overripe. It is very essential that the starters do not get 
overripe. The time when the germs are most numerous and 
most active in the starter is about the time when the sample 
coagulates. As soon as this stage has been reached, or just 
previous to coagulation, the starter should be cooled down to 
at least 50° F., or lower if possible This prevents any further 
growth of germs and the sample can be kept a short time 
without injury. 

Directions usually accompany each of the cultures, but the 
above will be found to produce good results with all of those 
mentioned in the above outline. 

By inoculating from 2% to 5% or more of the mother- 
starter into a large sample of pasteurized milk, any desired 
amount of starter can be prepared. In selecting this amount 
of milk, as much care as possible should be taken in order to 
select the best kind of milk, and keep it from being contaminated. 
When this large sample of starter is at the proper stage of 
coagulation, it should be used at once, or else cooled down to 
about 50° F. The amount of mother-starter with which to 
inoculate the large sample of starter may vary a httle with- 
out any bad effects. If the large sample of starter is to be 
ready for use in a short time, a larger portion of the mother- 
starter can be used for inoculation. If the temperature at 
wliich the starter is set and the amount of mother-starter used 



222 BUTTER-MAKING. 

for inoculation are the same from day to day, the starter will 
be ripe at nearly the same hour every day, and, consequently, 
more uniform ripening results can be obtained. The notice- 
able coagulation of the starter when skim-milk is used ^\dll 
usually take place when there is about .6% of acidity. A 
slight coagulation will take place when there is about .5% of 
acidity, but it is hardly noticeable. The coagulation-point may 
vary with different samples of milk. 

If a mother-starter is to be kept any length of time it 
should be inoculated into a sample of good fresh pasteurized 
milk about every other day. If a mother-starter, or starter 
of any kind, is allowed to stand too long at a low temperature, 
the desirable germs will become dormant, and some undesirable 
germs will gradually gain a foothold. It is a good plan to 
carry any mother-starter along for two or three days before it 
is used to inoculate a large sample of milk. When the mother- 
starter is first prepared it sometimes contains an undesirable 
taste and smell from the medium in wliich the germs were 
put up at the laboratory. Tliis smeh and taste is eUminated 
by carrying it on two or three days previous to its use. 

While the starter, or mother-starter, is in the stage of 
ripening it should occasionally be gently stirred. As soon as 
coagulation of the milk begins, then starters of any kind should 
never be stirred. If a sample of coagulated milk is stirred 
before it is ready for use, it is more hkely to "whey off." 

Length of Time a Starter Can be Carried. — In tliis country, 
even if special precautions are taken, it seems almost im- 
possible to carry on a starter for more than four weeks -without 
having undesirable ferments enter. The length of time a starter 
can be carried undoubtedly depends upon conditions, and the 
care with which it has been handled. When a starter is properly 
prepared, cooled gradually before coagulation, and not overri- 
pened, it will contain a smooth soft curd, and retain its mild acid 
flavor for at least a month. The Danes, who use starters in 
butter- making more regularly than any other people, are able to 
carry a starter along for six months or more without renewing it. 



STARTERS. 223 

It is a good plan to keep at least two different kinds of 
starter by carrjdng them on from day to day in small quart 
jars. Then if one should happen to "go off," the other one 
can be used instead. 

Poor Starters. — Many unsuccessful results from the use of 
starters for cream-ripening have been reported. The failure 
can be traced to the improper use of starters. If starters are 
good they mil never bring about poorer results than are ob- 
tained without the use of them. Owing to the fact that it is 
difficult to keep the same starter in a good condition very 
long, many starters are used which develop abnormal fermenta- 
tions in cream. A shghtly acid, somewhat bitter taste, and a 
slimy condition of the starter are defects which are very com- 
mon. These concUtions seem to be brought about cliiefly by 
overripening it at a high temperature, and keeping it a long 
time at a low temperature before using it. Shmy fermenta- 
tion is very common in starters which have been carried on 
for a time. Whenever tliis shmy ferment develops in the 
starter it can be noticed in the cream and starter both, by the 
acid not developing so rapidly as when the proper acid-pro- 
ducing ferment is present. It seems almost impossible to 
develop any more than about .5% of acidity in 30% cream; 
while if the proper ferment were present, about .7% could be 
developed. A decrease in the quahty of butter accompanies 
the development of this ferment in the cream. 

^Mienever it is found that a starter is not in as. good condi- 
tion as it ought to be, it should not be used, as a poor starter 
is worse than none at all. The buttermilk from the previous 
cream can sometimes be used advantageously until a new 
starter can be prepared. 

Underripening and Overripening of Starters. — The effect 
of overripening starters has already been mentioned under the 
''Preparation of Mother-starters.'"' The question of under- 
ripening starters is also of importance. It is a weh-known fact 
that just about the time when the milk begins to turn sour^ 
that is, when the sourness can just be recognized by the taste, 



224 BUTTER-MAKING. 

it has a rather disagreeable flavor. After more acid develops 
the undesirable flavor largely disappears, and the milk assumes 
a clean, desirable acid taste. The reasons for this has recently 
been accounted for by Storch, the well-known authority on 
starters. He claims that this disagreeable flavor is due to the 
action of undesirable organisms, during the first souring stage. 
As the souring progresses these germs are subdued and grad- 
ually crowded out by the desirable acid-producing types. 

In the preparation of a starter the probabihties are that 
some of these undesirable types of germs are present. At least 
it is safer to go on the assumption that they are present. This 
makes the underripening of starters just as important to guard 
against as overripening. 

Amount of Starter to Use. — The amount of starter will vary 
under different conditions. It may vary from none at all the 
as much as 50% of the cream to be ripened. The quahty of 
cream is one of the factors that needs to be considered. Raw 
cream and old cream each require a large starter, especially if 
the cream is thick enough so as to permit of being reduced in 
thickness. Good pasteurized cream does not need a larger 
starter than about 10% of the cream to be ripened. 

The amount of starter to use also depends somewhat upon 
the general creamery conditions. In some creameries all the 
cream is received in a very sour and poor condition, and faciU- 
ties for getting milk for preparation of starters are often very 
poor. Under such conditions it is questionable whether it 
would be profitable to use starters at all. The amount of 
starter to use chiefly depends upon the degree of rapidity of 
ripening desired, and upon the temperature of the cream. If it 
is desirable to ripen quickly, then a comparatively large starter 
(15% to 25%) should be added, and the ripening temperature 
should be comparatively high (about 80° F.). If slow ripening 
is desired, then less starter can be used. Enough, however, should 
be used to control the fermentation in the cream (about 10% 
to 15%), and the ripening temperature may be lower, between 
60° and 70° F. More starter should be used in the winter. 



STARTERS. 



225 



Use of Starter-cans. — In the past, ordinary tin shot-gun 
cans have chiefly been used for the preparation of starters, 
and have given good results. Many makers still use such cans 
in preference to recently invented starter-cans. 





Fig. 133.— The Victor 
starter-can. 



Fig. 134. — Emily's perfection 
starter-can. 



The earhest starter-cans were made of Hght material and did 
not last long. These defects, however, have largely been done 
away with, and the use of starter-cans certainly is an improve- 
ment over the old method of preparing the starters in several 
smaller cans. 

These starter-cans are jacketed, so that the temperature can 
be controlled by using hot or cold water, or ice, as demanded, 
in the jacket. All of the starter-cans have an agitator, which 
is operated with a belt. 



CHAPTER XVI. 

CHURNING AND WASHING BUTTER. 

Definition. — By churning we understand the .agitation of 
cream to such an extent as to bring the fat-globules together 
into masses of butter of such size as to enable the maker to 
separate them from the buttermilk. 

The agitation may be brought about in several different 




Fig. 135. — Ancient method of churning 
in skin bags. 




Fig. 136.— The Dash churn. 



ways, and by different shaped devices, which are called churns. 
The methods of churning, hke the process of separation, began 
with primitive methods. The ancients churned their milk, 
without separation, in bags made from the skins of animals. 
The next step in advance was to place milk or cream in bottles 
or jars, and then to shake them. This latter method of churn- 

226 



CHURNING AND WASHING BUTTER. 227 

ing cream in bottles is yet in use in many of the smaller house- 
holds of Europe, where the amount of cream is Umited to a 
small quantity donated by cow-owners. The next step toward 
churning on a large scale was to get a large wooden box or 
barrel run by power or by hand. The churns which are in use 
at the present time in American butter-factories are termed 
''combined churns." They are so arranged as to admit of 
churning, washing, salting, and working without removing the 
butter from the churn. This style of churn is now being in- 
troduced into Europe. Owing to their superior worth they will 
soon be in general use there as well as here. They keep flies 
away from the butter during fly time; the temperature of the 
butter can be controlled in the churn, and the handhng of the 
butter during salting and working is obviated. 

Conditions Affecting the Churnability of Cream. 

Temperature. — The temperature of cream is one of the most 
influential factors in determining the churnabihty of cream. 




Fig. 137. — The Dairy Queen combined churn. 

The higher the temperature of the cream, the sooner the churn- 
ing process will be completed. Too high a churning tempera- 
ture, however, is not desirable. It causes the butter to come 
in soft lumps instead of in a flaky granular form. This is 
deleterious to the quality of the butter. It causes, first, a greasy 
texture of the butter, and, secondly, it causes the incorporation 



228 



BUTTER-MAKING. 



in the butter of too much buttermilk. This buttermilk contains 
sugar, curd, and water, which, when present together in butter, 
are likely to sour and in other ways deteriorate the butter. 
Curd and sugar should be excluded from butter as much as 
possible, in order to eliminate food for bacteria which may be 
present. An excess of curd is also favorable for the forma- 
tion of mottles.* 

Too low a temperature is also undesirable, although it is 




Fig. 138. — The Victor combined churn. 

better to have the temperature a little low rather than too high. 
When the churning temperature is too low, difficult churning 
is hkely to occur. Cream at a low temperature becomes more 
viscous. On agitation in the churn such cream if it is very 
thick will adhere to the sides of the churn and rotate with 't 
without agitating; consequently no churning will take place. 
Too low a temperature brings the butter in such a firm condi- 
tion that it takes up salt with difficulty, and when this hard 
butter is being worked, a large portion of the water in the 

* Bui. No. 263, Geneva, N. Y. 



CHUENING AND WASHING BUTTER. 229 

butter is expressed, and the overrun will be lessened to a great 
extent without increasing the commercial value of the butter. 

The degree of hardness of the fat in the cream is the govern- 
ing factor in deciding the churning temperature. The churn- 
ing temperature will vary a great deal in different locahties. 
The hardness of the fat depends upon (1) the season of the year; 
(2) the individuality of cow; (3) the stage of lactation period; 




Fig. 139. — ^The Squeezer combined churn. 

and (4) the kind of food fed to the cows. All these factors 
influence the melting-point of butter-fat. The liighei^ the 
melting-point of butter-fat is, the higher the churning tempera- 
ture, and the lower the melting-point of the fat, the lower the 
churning temperature. 

1. During the spring the cows yield milk containing a larger 
proportion of soft fats; consequently the churning tempera- 
ture is always lower in the spring than in the fall or winter. 
During mnter, when the cows are fed on dry food cliiefly, the 
harder fats increase in quantity, and consequently a higher 
churning temperature is necessary during that time. 

2. Some animals produce milk containing a larger proportion 
of softer fats than do other animals. It is said that the differ- 
ence in this respect is more marked in certain breeds. It is 
maintained that the cows of the Jersey breed produce milk con- 
taining a larger proportion of the softer fats than do any of the 
other breeds. 

3. The period of lactation also affects the melting-point of 
butter-fat. When a cow is fresh she yields a larger proportion 



230 



BUTTER-MAKING. 



of the soft fats than she does later on in the lactation period. 
With this increase in the proportion of the hard fats in the 
advancement of the lactation period, the fat-globules become 
smaller. This, together with the increased hardness of the fat, 
causes difficult churning at times. It can readily be seen that 
the larger the fat-globules are the greater are the chances for 
these globules to strike each other during agitation in the 
churning process. 

4. The nature of the food fed affects the melting-point of 
butter to a considerable extent. Cotton-seed and its by- 




FiG. 140. — The Disbrow combined churn. 



products have been demonstrated thoroughly by several investi- 
gators to cause butter to become hard. When a large amount 
of cottonseed is fed, the butter assumes a crumbly, tallowy, 
hard condition; while linseed meal, and practically all succulent 
foods tend to decrease the melting-point of butter-fat. 

According to the above it can be concluded that the churning 
temperature may vary between wide hmits, but the average 
desirable churning temperature under normal conditions is 



CHURNING AND WASHING BUTTER. 



231 



between 50° and 60° F. Any conditions which tend to harden 
the butter-fat will require a comparatively high churning tem- 
perature; and any conditions tending to soften the butter-fat 
will require a lowering of the churning temperature. The 
lower the temperature at which the churning can be success- 
fully accomphshed, the more complete will be the churning; 
that is, the less fat will remain in the buttermilk. 




Fig. 141. — The Simplex combined churn, with worker detached. 

Richness of Cream. — The amount of fat in the cream affects 
the churnabihty of it considerably. The richer the cream the 
sooner will be the completion of the churning, that is, providing 
the cream is not rich enough to be so thick as to cause the cream 
to adhere to the inside of the churn and thus escape being 
agitated. If rich cream is churned at a high temperature the 
butter will come in a remarkably short time, providing all other 



232 



BUTTER-MAKING. 



conditions are favorable. Thin cream churns much more slowly, 
and can be churned at a higher temperature than thick cream, 
without injuring the quality of the butter. When rich cream 
is churned at a high temperature, and the butter comes in a 
short time (about ten minutes), the butter will usually be greasy 
in body, and will contain a great deal of buttermilk, which will 
be more or less difficult to remove on wasliing. When thick 
cream is being churned, the butter does not break in the form 
of small round granules, as it does when thin cream is churned. 
When thick cream is churned at as high a temperature as is 
consistent with getting a good texture, the best results are 
obtained. In the first place, rich cream produces less butter- 
milk, consequently less fat will be lost in the buttermilk. This 
would tend to increase the overrun. Secondly, the breakhig 
of the butter at the end of the churning will be such as to 
cause the granules to appear large and flaky, rather than small 
round granules. The more flaky granules of butter will retain 




Fig. 142. — The Simplex churn with worker attached. 

more moisture than the small, harder granules under the same 
treatment. Experiments show that when different thicknesses 
of cream (thin cream containing on an average 22% of fat, 
and thick cream 36% of fat) are churned, there is a difference 
of about 3% in the moisture- content of the butter. The 



CHURXIXG AXD WASHIXG BUTTER. 



233 



average churning temperatures of cream and wash-water in these 
experiments were 56° and 53° F. respectively. 

AMien thick cream is churned, and the temperature is 
moderately high, it is almost impossible to churn the butter 
into granules. Tliis condition causes butter from thick cream 
to contain more moisture than butter from tliin cream. 

Amount of Cream in Churn. — ^lien the churn is about one- 
tliird full, the greatest degree of agitation is obtained, and con- 




FiG. 143. — Danish churns and frame for holding them. 

sequently a quicker churning. If a small amomit of cream is 
being churned, it is often difficult to gather the butter properly. 
If the cream is tliin. the granules are thrown about in such a 
way that they are gathered with chfficulty. If the cream is 
tliick. the smaU amount of cream -uill adhere to the inside of the 
chm-n. and in that way delay the completion of the churnine;. 
It is a common opinion that less overrim is obtained from 



234 BUTTER-MAKING. 

a small churning than from a large churning. It is safe to say 
that if it were possible to maintain all conditions alike, especially 
as to temperature and degree of churning, there would be no 
difference in the moisture-content of the butter made from 
churnings of different sizes. When there is only a small amount 
in the churn, the atmospheric temperature is likely to raise or 
lower the temperature of the cream. If the atmosphere is 
warm, then the butter from the small churning is more hkely 
to be soft. A small amount of cream in the churn is also more 
likely to be overchurncd than a larger amount of cream. These 
two factors would tend to increase the amount of water in the 
butter. In mixing the salt with a comparatively large amount 
of butter, less working is necessary. Much of the butter is 
mixed in the churn without going through the workers, and con- 
sequently less moisture will be expressed from the butter. With 
the same number of revolutions of the churn the butter from 
the small churning is worked correspondingly more than the 
butter from a larger churning. Medium firm butter, to a cer- 
tain Umit, loses about .2% of moisture for every revolution that 
it is overworked in the absence of water. 

Degree of Ripeness. — The riper the cream is, all other con- 
ditions being the same, the easier it w^ill churn. Sweet cream 
is viscous, and consequently the fat-globules will not unite as 
readily. The acid developed in the cream seems to cut or 
reduce the viscosity of the cream, although it causes it to become 
thicker in its consistency. Cream in an advanced stage of 
ripening is brittle, so to speak. That is, if a sample of the 
properly soured cream is poured from a dipper it will not string 
but break off in lumps. 

If very thin cream is overripened, the curd is coagulated. 
When this thickly coagulated cream is churned, the soHd curd 
breaks up into small curdy lumps. These small lumps of curd 
are likely to incorporate themselves in the body of the butter 
and injure its quality, and also its keeping quahty. If tliin 
cream has been overripened, it should be strained well, and 
care should be taken not to churn it to such a degree as to 



CHURXIXG AND WASHING BUTTER. 



235 



unite the granules into lumps before the churn is stopped. By- 
stopping the churn wliile the butter is in a granular form, the 
most of these curdy specks can be separated from the butter 
by copious wasliing. Some specks are hkely to remain in the 
butter when the cream is in such a condition, but by following 
the above plan enough of the specks can be removed from the 
butter so that it will not injure its commercial ciuahty. The 
degree of ripeness of cream does not have any effect upon the 




Fig. 144. — ^The chum-room in Trifolium Creamery, Demnark. 



composition of the butter, except in increasing the curd con- 
tent, as mentioned. 

Nature of Agitation. — The nature and degree of agitation of 
cream affect the churnabihty considerably. Many different 
kinds of churns are on the market at the present time. The ro- 
tary drum-churns, now used almost universally in this country, 
are claimed to give the greatest degree of agitation; that is, 
pro^dding the churn revolves at a proper rate of speed. If 



236 BUTTER-MAKING. 

the speed is so great as to cause the cream to be influenced by 
the centrifugal force generated, rotating it with the churn, 
then no agitation will take place. Consequently the churning 
process will be delayed, if not entirely prevented. If the 
speed of the churn is too slow, the degree of agitation of 
the cream will not be at its maximum, as the cream will tend 
to remain at the lowest portion of the churn without being 
agitated. 

In the old-fashioned dash-churn the cream was not exposed 
to much agitation. In Europe the upright barrel-churn with 
rotary stirrers inside is mostly used. It takes longer to churn 
in this churn than in American churns. However, it gives good 
satisfaction. 

The proper speed of the combined churn, — that is, the speed 
at which the greatest degree of agitation is brought about, — 
cannot be given here, as it varies with the different diameters 
of the churns. The directions given with the churns from the 
manufacturing companies should be followed. So far as known 
the quahty and composition of butter obtained from churning 
at a low speed, and at a rapid speed, do not vary. 

Size of Fat-globules. — Cream containing large fat-globules 
churns more quickly than cream containing small globules. A 
more exhaustive churning can also be obtained from cream 
containing mostly large globules. It is, however, impossible 
to obtain cream which does not contain any of the small globules. 
The minute globules are always difficult to remove from the 
serum, whether it be in the churning or in the separation. In 
the churning there is a certain force which always tends to hold 
the globules in place. This force acts in a correspondingly 
greater degree upon the small globules. They are held in 
position and move only when the cream is exposed to agitation. 
Cream containing larger globules allows them to escape from 
their position with greater ease than does cream containing 
the minute globules. The globules which are not removed from 
the buttermilk during the churning process are largely of the 
small type. 




a 

o 

q; 
C 

S 



O 



3 



238 



BUTTER-MAKING. 



Straining of Cream. — Before the cream is transferred from 
the ripening-vat to the churn it should be strained through a 
fine perforated tin strainer. This can be conveniently done 
during the changing of the cream from the ripening-vat to the 
churn. Special strainers are now manufactured which can 
be hooked onto the churn, and the cream can run directly from 
the ripening-vat through the strainer into the churn. This 
straining of the cream separates all the lumps wliich are 
likely to appear. It also separates any other coarse impurities 
which may be present. If these impurities were not sepa- 
rated they would probably be embodied in the butter and 
cause an unsightly appearance. They would also be likely to 
injure the keeping quaUty of the butter, but this would depend, 
of course, upon the character of the im23urities. 




Fig. 146. — Cream and milk strainer. 

Color. — In order to maintain a uniform color in the butter 
during the different seasons, it is essential that some artificial 
color be added at certain times. During the latter part of 
May and the fore part of June the butter has a rich yellow 
color, which is accepted as the standard color of butter. This 
is often referred to as the "June color." 

There are several different butter-colors on the market, for 
which special merits are claimed. All the colors, so far as 
known, are efficient in imparting color to the butter without 
materially coloring the buttermilk. A good butter- color should 
be a substance which does not impart a bad smell or taste to 
the butter. It should possess strong coloring properties, so 
that very little of it would have to be added in order to 
impart the desirable color. It should not be injurious to health. 



CHURNING AND WASHING BUTTER. 239 

Some colors are prepared from the fruit of the annato tree, 
which grows in the East Indies and South America. The flesh 
of this fruit is dissolved in some oil, such as sesame or hemp. 

Before any of the proper commercial butter-colors were put 
upon the market, extracts of carrots, marigold, saffron, and 
annato were used. The yolk of eggs has also been used to 
some extent. It is said that carrot-juice is the most healthful 
butter-color. 

The amount of color to add depends upon the market 
requirements, and upon the season of the year. As was men- 
tioned before, in June little or no color should be added. As 
the summer season advances the amount of color added can be 
gradually increased. During winter, while the cows are on 
dry feed, the maximum amount of color is generally used. Color 
recjuirements of the butter vary considerably at the same season 
of the year. American markets demand a higher color than 
European markets. The northern markets desire a light straw 
color, while the southern markets want a deeper color, almost 
an orange color. The Jewish trade requires uncolored butter. 
In some of the European countries no color is used. The 
English market, which is the greatest butter market in the 
world, demands butter that has a very Hght straw color. The 
main object in coloring butter is to maintain a uniform color 
during the different seasons of the year. The amount of color 
to add during the different seasons will usually vary between 
none to a trifle over two ounces for every 100 pounds of fat. 

The color should be added to the cream before the churn 
has been started. If this has not been done, the butter can be 
colored by mixing the color with the salt. The salt should 
then be well distributed and worked into the butter until the 
body of the butter assumes a uniform color. The chief ob- 
jection to this method is, that it is difficult to work in the color 
thoroughly without injuring the butter. 

When to Stop the Churning. — Different makers have various 
ways of ascertaining when the churning process has been com- 
pleted. Some determine the proper churning stage by the size 



240 BUTTER-MAKING. 

of granules. Others by the height at which the butter floats 
in the buttermilk. Others again depend upon the appearance 
of the buttermilk. It is well to let all of these factors influence 
the operator in deciding when the churn should be stopped. 
Any one of these factors may not be sufficient indication to 
insure the proper time to stop. 

The size of the granules is the most common factor that 
determines the time when the churn should be stopped. It 
has been a general rule in the past to stop the churning when 
the granules are a httle larger than wheat-kernels. As a rule 
it is safer to carry the churning on a little further until the 
granules increase to the size of corn-kernels, irregular and 
flaky in shape. At this stage the buttermilk will usually appear 
bluish in color, and the butter is raised above the buttermilk 
a considerable distance. When the butter is churned to too 
small granules, many of them will go through the strainer into 
the buttermilk, and cause a considerable loss. When butter 
in such shape is washed in medium-cold wash-water, the granules 
continue to remain in a separate state. When salt is added, 
the moisture is extracted from them, and the water is likely 
to be caught in holes and crevices during the working and 
cause leaky butter. If the churning is carried on a httle further, 
the granules will not escape into the buttermilk. The churn- 
ing is more complete, and the moisture will be incorporated in 
a better condition. 

Overchurning should be avoided as much as underchurning. 
If butter is overchurned in the buttermilk, it will retain a 
large amount of the buttermilk, which will be very difficult 
to remove by washing. Overchurning butter, especially at a 
medium-high temperature, is very effective in increasing the 
moisture-content of butter, and should be guarded against for 
that reason. Butter containing more than 16% water is not 
permissible on the American market. 

When cream is in a poor condition it should not be over- 
churned, as the incorporation of buttermilk produces a very 
rank and unclean flavor in the butter. Cream in such condi- 



CHURNING AND WASHING BUTTER. 



241 



tion also contains many undesirable germs, which, when in- 
corporated into the butter, will cause it to deteriorate to a great 
extent. When the cream is in poor condition, the churn should 
be stopped as early as is consistent with the completeness of 
churning. The buttermilk should be removed and the butter 
washed thoroughly in good clean and pure wash-water. If 




Fig. 147. — Butter from 1 lb. of fat in cylinders, showing the effect of differ- 
ent percentages of water upon quantity. The water-content of these 
samples ranges between 8% and 19%. 



the wash-water is added while the butter is in this granular 
condition, the buttermilk can be very effectively removed. 
If one washing is not sufficient, wash three or four times. In 
such a case the temperature should be low. If the temperature 
of the wash-water is high, and the butter is washed excessively, 
it will contain too much moisture when it is finished, and is 
hkely to be salvy. By washing with water at a low temperature 
the butter will not incorporate so much water. What it does 



242 



BUTTER-MAKING. 




Fig. 148. — Butter sample, 

15.61% water. 



Fig. 1 49 . — Butter sample, 
15.31% water. 




Fig. 153. — Butter sample, 13.37% water; leaky, 2% brine. 

Microscopical views showing condition of water in butter. Fig. 148 shows that 
the water has been incorporated in the form of very minute particles. 
Storch found from nine million to sixteen million water particles per 
cubic millimeter. Such butter appears dry and a little dull. Fig. 149 
shows the water incorporated in medium-small particles. There was 
on an average three and three-fifths millions of water particles per cubic 
millimeter in such butter. Fig. 150 shows condition of water in leaky 
butter. Storch found about two and one-half million water particles 
per cubic millimeter in butter having such a body. (Views by 
Storch.) 



CHURNING AND WASHING BUTTER. 243 

incorporate in excess, will, as a rule, be expressed during the 
working of the butter — a result due to its firmness. 

If the attempt is made to incorporate water by working 
the butter in water after the salt has been added, while the 
butter is in a hard, granular condition, it will usually appear 
leaky. 

If cream is in a good condition, overchurning to a small 
extent does not produce any bad results. The germs which 
are present in pure and well-ripened cream are not deleterious 
to the keeping quality of the butter. The amount of butter- 
milk incorporated in the butter is not sufficient to cause any 
bad effects upon its quaUty. If the cream is in proper condi- 
tion it is difficult to incorporate any more than 3% of curd 
into the butter, "\^'^lile overchurning is not to be recommended, 
if it is at any time desirable, it should be done in the wash- 
water rather than in the buttermilk. 

Churning Mixed, Sweet, and Sour Cream. — When two lots of 
cream are to be churned, one sweet and the other sour, they 
should be churned separately. If the two lots of cream are 
mixed together, the sour cream churns more quickly than the 
sweet cream. As a consequence the churn is likely to be 
stopped before the fat from the sweet cream has been com- 
pletely separated from the serum. 

At some of the creameries conditions are such that the 
operator may be tempted to mix the two lots of cream. Where 
sweet cream arrives at the creamery just previous to churning 
time, it is advisable not to mix the sweet cream T^dth the sour. 
It is, as a rule, better to carry the sweet cream over to the 
next churning, or, if necessarj", churn it separately. 

Difficult Churning. — DifRcult churnings in creameries are 
not very common. In farm butter-making it is more frequent. 
EspeciaUy is this so in the fall. At this time the cows are 
usually well advanced in the period of lactation, and early in 
the ^dnter they are often fed on food wliich causes hard butter- 
fat, as described under "Effect of Food upon Fat." In the 
fall or early winter, a large portion of the milk is usually obtained 



244 BUTTER-MAKING. 

from strippers, or cows almost dried up. Such milk contains a 
large portion of the small fat-globules. Difficult churning; 
resulting from such conditions can usually be remedied by 
ripening to a higher degree of acidity and churning the cream 
at a higher temperature. 

Complaints are occasionally heard of difficult churning 
which cannot be remedied by such treatment. Sometimes 
cream froths, and will not agitate in the churn. Such a frothy 
condition has in some cases been found to occur even though 
the cream may seem to be in an ideal condition for churning. 
It is beUeved by some, notably Hertz, that such a condition in 
the cream is brought about by a disease of the cow. Weigman 
has studied and isolated a ferment which caused a soapy condi- 
tion of milk and cream. It is possible that such exceedingly 
difficult cases in churning may be due to a disease of the cow, 
and it may also be due to certain ferments that produce a soapy 
condition of the cream. 

If thick cream at a very low temperature is put into the 
churn, it sometimes produces difficult churning. When such 
cream is first agitated in the churn it incorporates considerable 
air. This air, together with the various gases developed at a 
low temperature does not readily escape. The viscosity of 
it is so great that it will not release the air present. As a 
consequence it assumes a stiff consistency, much the same as 
the beaten white of an egg. If cream froths in the churn as 
mentioned, a httle warm water thrown on the outside of the 
churn will often start the agitation of the cream within. If 
a combined churn is used the rollers may be put in gear, and 
the churn revolved in slow gear. This will often start the 
cream to agitate. If these two remedies are not sufficient, a 
little water, luke-warm if necessary, may be added directly to the 
cream. By letting the churn stand a short time, the cream will 
usually condense into a Hquid form again, and many times the 
churning process can then be completed. This latter method, how- 
ever, usually requires more time than can be profitably spared. 
If the churning difficulty is of a serious nature the remedies are: 



CHURNING AND WASHING BUTTER 245 

(1) If produced by a certain cow, or herd, find out whether 
it is produced by a fermentative process, or by other abnormal 
conditions of the cow. 

(2) Change the food of the cow. A succulent food will 
usually cause the cow to secrete more milk, and of a different 
nature. 

(3) If produced by a ferment, endeavor to control the fer- 
mentation as previously described. 

(4) Ripen the cream to a higher degree of acidity. 

(5) Skim thicker cream and churn at a higher tempera- 
ture. 

The last three methods will cure most cases of difficult 
churnings. 

Keeping Chum Sweet. — It has been mentioned before that 
butter absorbs foreign odors very readily. If the churn is not 
kept in a pure, sweet condition, the butter will be exposed to 
the undesirable odors and its commercial quahty will be im- 
paired. The best butter cannot be produced in a foul-smelhng 
churn. As churns often are not used every day, they very 
readily assume this impure condition, and it is essential that 
special care be taken in keeping them clean. 

The best method of keeping churns in good condition is 
to rinse the churn in two sets of scalding water at the end of 
each churning, then rinse in cold water and drain. Some 
prefer to turn the churn over with mouth down. Others prefer 
to allow the cover-hole to turn up. Neither of these methods 
is considered the most desirable. When the churn is turned 
with the cover-hole down, the remaining steam on the inside 
of the churn will not escape. It will condense inside of the 
churn, and cause the churn to remain in a damp condition 
overnight, or even longer. By turning the churn with the 
cover-hole up, the dust and other impurities from the atmos- 
phere are hkely to fall into the churn. The best method is to 
turn the churn over so that the cover-hole points to one side. 
The churn should be thoroughly drained first, otherwise some 
water will remain in the bottom of the churn. When the 



246 BUTTER-MAKING. 

churn is left with the cover-hole at one side, the steam can 
escape, and the heat absorbed from the wash-water will dry 
the churn thoroughly. Some makers do not rinse the churn 
with cold water. They simply scald the churn, or steam it, 
and then let the churn stand and dry. If this method is fol- 
lowed for any length of time the churn is likely to be short- 
Uved. The wood will, in a comparatively short time, get spongy. 
Such a condition will cause the churn to rot in a shorter time, 
and it will also allow the cream to enter the cracks and pores 
of the wood, making it more difficult to keep the churn in a 
sweet condition. If the churn is rinsed with cold water the major 
portion of the heat has been removed and still enough left to 
effectively dry the churn on the inside. 

Some makers prefer to keep the churn in a good condition 
by sprinkhng salt on the inside after washing. This is not to 
be recommended, as all churns contain more or less iron-ware 
on the inside. Salt, while a good germicide, causes the forma- 
tion of rust on all iron with which it comes in contact. After 
a time this rust will scale off to a certain extent and become 
incorporated with the butter. 

If the churn is treated daily in the manner described above 
and then at the end of the week treated with slacked lime, the 
churn can be kept in a good sweet condition. The hme should 
be freshly slacked and in a liquid condition when put in the 
churn. A pailful or two of this fluid will be sufficient for each 
churn. By rotating the churn a few times the lime will be 
spread all over the inside of the churn. Let the churn remain 
in this condition until ready for use again. When ready for 
use, put in some warm water, and the lime will readily come 
off. But if it has been allowed to remain in the churn too 
long, it will form a lime carbonate, and will be more difficult 
to remove. 

Lime is one of the best disinfectants and deodorizers that 
can be used in a creamery. Some of the best butter-makers 
use it every day on all the wooden utensils, such as on butter- 
workers, churns, etc. Lime can be used more advantageously 



CHURNING AND WASHING BUTTER. 247 

in American creameries tlian it is to-day. Many creameries 
would be in a much sweeter and purer condition if they were 
given a good coat of whitewash on the inside once a month. 
Refrigerators, wooden utensils, and rooms of any kind can be 
kept in a good sweet and pure condition by whitewashing or 
sprinkhng a little hme on them. 

Washing of Butter. 

Purpose of Washing. — The chief object of washing butter is 
to remove as much buttermilk as possible. The more impure 
the cream is, the greater is the importance of getting the butter 
thoroughly washed. In the winter, when it is cold, and the 
cream is in good condition, some makers do not wash the 
butter at all. But this is not a safe method. The removal 
of the buttermilk constituents should be as complete as con- 
ditions will permit. 

Temperature of Wash-water. — The temperature of wash- 
water should be as nearly like that of the cream when churned 
as is consistent with the other conditions. Extreme and rapid 
changes in temperature should always be avoided. Occasionally 
it is necessary to use water that is colder than the cream. At 
other times it is necessary to use wash-water at a higher tem- 
parature than that of the cream. If the butter churns soft, 
do not use ice-cold wash-water to chill the butter, as it has a 
tendency to give butter a tallowy appearance. Neither should 
hard butter be quickly softened by using wash-water at a very 
high temperature, as it is likely to cause the butter to assume 
a greasy and slushy texture. If it is necessary to change the 
degree of hardness of the butter, change it gradually by using 
water at a moderate temperature and allowing the butter to 
be in contact with it a longer time without agitating it much. 

Unless the butter is of very poor quality, excessive washing 
should be avoided. Cold water is said to absorb a considerable 
portion of the flavoring substances. If the quality of the 
butter is poor, many of the undesirable flavors and odors are re- 



248 BUTTER-MAKING. 

moved by excessive washing; while if the butter has a fine, rich 
flavor, it should be retained, and not extracted by washing 
the butter more than is needed. No definite temperature can 
be given, as the temperature of wash-water must vary accord- 
ing to the hardness of the butter when churned. 

If the temperature of the wash-water is too high, and the 
churning in the wash-water is continued a very long time, much 
water will be incorporated in the butter. If the butter is quite 
firm in the first place, and the temperature of the wash-water 
is not above 60° F., there is not much danger of getting too 
much water in the butter. Rapid changes in the degree of 
hardness of the butter in the presence of water are conducive 
to a high moisture-content. Very soft butter chilled in very 
cold water, and hard butter softened in very warm wash-water 
are two conditions which should be avoided. 

Kind of Wash-water to Use. — In the washing of butter, 
it is very essential that water used should be the best obtain- 
able. The creamery water-supply is evidently much better 
now than it was years ago. Pond- wells and shallow wells are 
gradually passing out of existence, but there are yet many 
shallow wells from which water is drawn for creamery purposes. 
Water from wells may appear to be pure, and yet contain 
germs which are deleterious to dairy products, and especially 
to the keeping quahty of butter. That water of average purity 
contains such germs has been demonstrated in this country, 
as well as in foreign countries. Shallow well-water contains 
on an average about 15,000 germs per cubic centimeter, but 
Miquel has found that a rapid power of multiphcation charac- 
terizes the bacteria in pure spring-water, while in impure water 
the multiphcation is slower. Water containing only this many 
germs is, as a rule, considered very pure. Most creameries, 
however, pump their water into a tank overhead in the creamery, 
where it is contaminated with bacteria and impurities of different 
kinds. 

Shallow wells are usually surrounded with conditions which 
do not guarantee a creamery pure water during the different 



CHURNING AND WASHING BUTTER. 



249 



seasons of the year. In the spring, when rains are frequent 
and heavy, unwholesome surface-water is hkely to seep in 
through the sides. Such wells may also serve as traps for 
small animals. The presence of an animal in the well is sure 




Fig. 151. — ^The shallow bamj^ard well -with pri\'y- vault and manure heaps 
near by. The water is likely to be contaminated from these any time. 
(Farmer's Bui. Xo. 4.3, U. S. Dept. of Agriculture.; 

to cause undesirable odors and a multitude of undesirable and 
putrefactive organisms. 

Water from deeply drilled wells, even if it is pure in so far 
as its germ-content is concerned, is in many cases turbid and 
sandy, and needs to go through a process of purification as much 
as does the shallow well-water. 



250 BUTTER-MAKING. 



Methods of Purifying Wash-water, 

There are two practical and effective methods of purifying 
wash-water, viz., (1) Filtration, and (2) Pasteurization. Which 
of these two methods is the most practicable and the most 
■effective in the creamery depends upon the conditions and 
upon the quahty of the water. In the case of water from deep 
wells, which contains Uttle or no organic matter, but at the 
same time is infested with undesirable germs, pasteurization 
is perhaps more expedient. Filtration, if the same degree of 
thoroughness is to be reached as in pasteurization, is a com- 
paratively slow process. Pasteurization of wash-water is a 
trifle more expensive than filtration. Wash-water can be 
pasteurized at the same time that the churning is being done, 
thus economizing in time and fuel. Pasteurization is quite 
effective in rendering the water germ-free, but it is not so 
effective in removing any organic matter or other tangible 
impurities which may be present. If the creamery does not 
already have a pasteurizer, filtration can be employed very 
profitably, and under average conditions it will perhaps give 
the best results. 

Filtration, — Filtration is inexpensive, and is a very efficient 
method of purifying wash- water. It seems strange that bacteria 
can be removed from water by passing through layers of sand, 
gravel, coke, and charcoal, but such is the case. Filtration 
is apphcable to all kinds of water; even if the water appears 
pure, it is well to filter it. Fewer germs and fewer varieties 
of micro-organisms are apparently found in deep well-water 
than is the case in water from surf ace- wells; hence the ferments 
which are present will have a free field for developing in the 
absence of competing forms. If a sample of water which is 
rich in micro-organisms is violently shaken with a certain amount 
of charcoal, coke, chalk, or similar substances, and then left 
for a time to settle, the pure layer of water at the top will be 
almost entirely free from germs, and in some cases entirely 



CHURNING AND WASHING BUTTER 251 

sterile. It used to be thought by older German investigators 
that these different filtering substances had almost miraculous 
power of removing organisms from water. 

The factors which are to be considered in successful filtra- 
tion are: 

(1) Storage capacity for unfiltered water. 

(2) Construction of filter-beds. 

(3) Rate of filtration. 

(4) Renewal of filter-beds. 

(1) Concerning the storage capacity, nearly all creameries 
have storage-tanks overhead in the creamery; so far as that 
is concerned, however, filtration can be successfully carried on 
continuously as well as intermittently. 

(2) The construction of the filter-bed used in the experi- 
ment carried on at the Iowa Experiment Station, Ames, Iowa, 
is as shown in Fig. 153. The approximate proportionate 
depth of each layer in the bed is as follows, beginning at 
the bottom: 

Two inches small flint stones; 22 inches fine sand; 12 
inches fine coke ; 9 inches charcoal ; 2 inches fine stone or coarse 
gravel. The layer of fine sand should not be less than 15 inches. 
It has been asserted that a few pieces of old iron mixed in 
the filter-bed are beneficial. Alum, lime, and copperas have 
been recommended for clarifying and deodorizing very impure 
water. As these substances are soluble they should not be used 
in filter-beds, which are intended for the filtration of water 
for potable purposes. The filtering-can was made from 22 
galvanized iron. The height of can is 48 inches; diameter, 
18 inches. The bottom of the can is slanting towards the 
faucet, or opening. Thus no water is permitted to stand on 
the bottom and afford opportunities for germs to accunuilate. 
On the inside are three plates. One lies horizontally, near the 
bottom, and upon it the filtering-material rests. Another lies 
on the top of the fine sand. Both of these plates were per- 
forated with many small holes. Near the top is placed a 
concave plate with a hole near the center. This plate directs 



252 



BUTTER-MAKING 



all the water to the center of the filter-bed, and thus the water 
gets the full benefit of the filtering process. The total cost of 
this filtering-can when complete was $11.11.' 






Coarse gravel S&t>°<3fe°o°iS?^ 






Gravel ^^•>^°6%iTT'^'fl'„%' 
Coarse eva.ve\ f°^'Pck§f§'^°4 




Fig. 152. Fig. 153. 

Fig. 152. — Filter-can: 1, overflow; 2, inlet of tap-water; 3, outlet of filtered 
water. 

Fig. 153. — Cross-section of filter-bed and can: 1, overflow; 2, inlet; 3, out- 
let of filtered water; 4, perforated galvanized-iron plate; 5, perforated 
galvanized-iron plate; 6, concave galvanized-iron plate with hole in 
center. 

(3) The rate of filtration is necessarily governed by the 
depth of the filter-bed^ the character of the material used, and 
its fineness. The water passes through the charcoal, coke, 
and gravel quite rapidly, yet the substances are very strong 
barriers to the passage of micro-organisms. The sand layer 
does not admit of so rapid filtration. Fine sand, however, is 
one of the best filtsring substances that can be had. The rate 
of filtration can be regulated by increasing or decreasing the 



CHURNING AND WASHING BUTTER. 253 

depth of the fine-sand layer. In a general way, the slower the 
rate of filtration is, the more thorough it is; and, vice versa, the 
more rapid the rate of filtration, the more incomplete is the 
removal of the bacteria. If the filter-bed is constructed as 
described above, the rate of filtration will be about 18 gallons 
per hour, and about 96% of all the germs present will be removed, 
together with the impurities present in suspension. 

(4) The filter used at the Iowa Experiment Station was in 
constant use for about three months, without having been 
changed. At the end of this time it did as efficient work as 
at any previous time. The length of time a filter-bed can be 
used without being changed depends upon the purity of the 
water to be filtered, and also upon which kind of filtration is 
used, the continuous or the intermittent. The more impure 
the water which has to be filtered, the oftener the filter-bed 
should be changed. Whenever the rate of filtration is decreased 
to such an extent as to make the process impracticable, the 
filter-bed should be taken out and cleaned. If the water 
to be filtered is of average purity, a change of the filtering-mate- 
rial once every four months is ordinarily sufficient, no matter 
whether continuous or intermittent filtration is used. A 
filter-bed may do efficient work even a longer time than this. 
The same filtering-material can be used again providing it is 
thoroughly washed previous to replacing it in the filtering-can. 

Kinds of Filtration. — The two kinds of filtration in use are 
(1) Continuous, and (2) Intermittent. 

By the continuous method of filtration the inflow of water 
into the can is' constant during night and day. The stream of 
water admitted into the filter-can is sufficient to cause the 
surface of the filter-bed to be covered with water all the time. 
This method excludes all oxygen from the filter-bed, except 
that which is in solution in the water. 

During the process of filtration a sHmy coat is deposited 
on the fine sand. This seems to be the real agent absolutely 
necessary in order to ehminate bacteria by a process of filtra- 
tion. A filter-bed without this sHmy deposit on it simply takes 



254 BUTTER-MAKING. 

out the coarse organic and inorganic matter held in suspension, 
without removing the bacteria. If some bacteria are removed 
with the matter held in suspension, others are carried along 
from the filter-bed. Owing to tliis, a new filter-bed must be 
kept in operation a few days before the filtered water can be 
considered pure and ready for use. The following table illus- 
trates how the germ-content of water is decreased as the process 
of filtration is carried on during the first few days : 

Filtered Un filtered 

Water, Tap-water, 

Germs per Germs per 
c. c. c. c. 

No. 1. Taken when filter-bed was first used 20,000 107 

" 2. " " " had worked 1 day 860 118 

" 3. " " " " " 3 days 370 96 

" 4. " " " " " 5 " 48 54 

" 5. " " " " " 7 " 3 73 

" 6. " " " " " 9 " 5 89 

It will be seen from the table that during the first three 
days the filter-bed was in use the filtered water contained more 
germs than the unfiltered. Good results were not obtained 
until the seventh day. In order to be on the safe side it is 
best to expose the filter-bed to continuous filtration for about 
nine days before the water is used. 

The sUmy coat referred to above is formed by certain germs. 
These germs then constitute the real agent of filtration. In 
order for these micro-organisms to do efficient work oxygen 
is essential. Well-water of average purity contains enough 
oxygen in solution without employing an intermittent process of 
filtration, and consequently for creamery purposes the con- 
tinuous method of filtration is to be recommended. 

Intermittent. — The intermittent process of filtration is used 
where comparatively impure water is being purified, such as 
in purifying water for large cities. If the continuous process 
of filtration were employed in such instances, the filtered 
water would not be free from germs, due to the fact that impure 
river-water does not carry enough oxj^gen in solution to supply 
the germs which form the real filtering agency. 



CHURNING AND WASHING BUTTER. 255 

If the intermittent process is used, the first water filtered 
after the intervening period should not be used. During the 
intermission, or during the time that the water is shut off, 
germs develop and come through the filter-bed with the water 
that is filtered. 

Advantages of Purifying Wash-water for Butter. — The chief 
advantage of purifying wash-water for butter is that the keeping 
quahty of the butter is improved, and if the proper skill and 
care have been applied in the other steps of manufacture, a pure 
sanitary product is obtained. The sanitary efficiency reached 
by purifying the wash-water constitutes no small consideration. 
Germs producing contagious diseases are thus checked from 
spreading. 



CHAPTER XVII. 

SALTING AND WORKING OF BUTTER. 

Objects of Salting. — The chief objects of salting are: (1) 
to impart a desirable flavor; (2) to increase the keeping quality 
of butter; and (3) to facilitate the removal of buttermilk. 

Amount of Salt to Use to Produce Proper Flavor. — The proper 
amount of salt to use in order to impart a desirable flavor 
depends chiefly upon the market. Some consumers prefer a 
medium high salt-content in butter; others, again, Uke butter 
which contains very Uttle salt. The Enghsh market demands 
rather light-salted butter. In fact, this is the case with prac- 
tically all European markets. American markets, as a rule, 
demand comparatively liigh-salted butter, as much as will 
properly dissolve in the butter. Parisian markets and some 
markets in southern Germany require no salt in it at all. The 
salt-content of butter may vary between nothing and 4%. 
Butter containing as much as 4% salt is, as a rule, too highly 
salted. When it contains this much salt, part of the salt is 
usually present in an undissolved condition. Those who hke 
good butter prefer butter that contains the salt thoroughly 
dissolved and well distributed. 

The amount of salt to be added should be based upon the 
least variable factor. Some creamerymen measure the amount 
of salt according to the amount of cream in the churn. While 
the box-churn and Mason butter-worker were being used, many 
makers preferred to weigh the butter as it was transferred from 
the churn to the worker. The method mostly in use now, and to 
be recommended, is to base the amount of salt upon the number 
of pounds of fat. The amount of salt to use per pound of fat 

256 



SALTING AND WORKING OF BUTTER. 257 

varies, therefore, according to the conditions mentioned below, 
and also according to local conditions. Usually fro:a half 
an ounce to one and a haK ounces of salt per pound of butter- 
fat is most suitable. In whole- milk creameries the salt is 
often estimated per hundredweight or per thousand pounds of 
milk. 

To get the butter salted uniformly from day to dav is very 
important, as a small variation in the salt-content has a greater 
effect upon the quaUty of butter than has a small variation 
in any of the other butter constituents. A variation of 1% 
to 2% in the salt-content can very easily be detected by the 
consumer, while that much variation in any one of the other 
constituents could not be readily noticed. 

The conditions upon which the proper amount of salt 
depend are: First, the amount and condition of moisture in 
the butter at the time the salt is added. If there is a great 
deal of loose moisture in the butter, more salt is nece.ssary. 
This is due to the fact that the salt will go into solution in the 
water and be expressed during working. Secondly, it depends 
upon the amount of working the butter receives, and at what 
time the bulk of working is done, after the salt has been added. 
If the butter is medium firm, moisture in the form of brine 
is being expressed during the working. Consequently, the more 
butter is worked, up to a certain hmit, the more brine is being 
expressed, and the more salt .should be added to the butter. 
Thirdly, the amount of salt to add depends also upon the size 
of the butter granules at the time the salt is being added, and 
the hardness and softness of the butter. If the granules are 
xerv smaU. and quite hard, they take salt with difficulty. The 
salt attracts also more moisture from these small granules than 
from larger ones, which will escape in the form of brine. 
If the butter is present in a rather soft, lumpy condition at 
the time the salt is added, and there is no water in the churn, 
ver}' httle salt is wasted in the form of brine, consequently 
less salt Ls necessar}' in the first place. 

It is undoubtedlv due to these facts that the salt-content 



258 BUTTER-MAKING. 

and the condition of salt in butter vary so much at the different 
creameries; they even vary considerably from one churning 
to another at the same creamery. If conditions are uniform 
in the creamery from day to day, the amount of salt to add 
to butter, and the amount of salt retained in the butter when 
finished, will be comparatively uniform. 

It should be mentioned in tliis connection that butter made 
from very good cream should not be salted too heavily. Butter 
made from a rather poor quality of cream may be salted corre- 
spondingly heavier. This is due to the fact that the heavy 
salty taste covers some of the undesirable flavors in the butter. 
If the butter-flavors are good, they should not be hidden by 
a heavy salty taste. If the butter-flavors are poor, then it 
may be policy to partially cover them up with a medium-heavy 
salty flavor. 

Effects of Salt upon Keeping Properties. — Tliat salt is anti- 
septic is no longer a doubt. It has been domonstrated in 
laboratory work with butter that the growth of certain germs, 
isolated from butter, can be completely checked by the addi- 
tion of a certain amount of salt to the medium in which they 
are inoculated. Bouska * found that a yeast isolated from 
butter showed luxuriant growth in a medium containing 2% 
of salt in forty-eight hours, and only a trace in 4% of salt. 
The same germ showed only a trace of growth in a 6% salt 
medium after five days. 

The ordinary bread-mould, Penicillium glauami, was iso- 
lated from butter and showed noticeable growth in a 9% salt 
medium in two days, and only a trace in a 10% solution during 
the same time. A spore-bearing bacillus isolated from butter 
produced only a trace of growth in a 4% salt medium. No 
growth occurred at all in a medium containing 6% of salt. 
Another gas-producing organism was also isolated from butter 
and only a weakened growth was produced in a medium con- 
taining 4% of salt. 

* Iowa Ex. Sta., Bui. 80. 



SALTING AND WORKING OF BUTTER. 259 

If it were practicable and consistent wdth the demand of the 
consumers, so far as the keeping properties of butter is con- 
cerned, it would be ad\dsable to salt butter as Mglily as 6%. 
This much salt would tend to a large extent to check deterio- 
ration of the butter due to bacterial growth. 

That salt promotes the keeping quaUty of butter has also 
been demonstrated in a practical way during the Iowa Educa- 
tional Contest in 1903. Fifty samples of butter containing 2J% 
or more of salt were scored off in New York, on an average, 
2.38 points, while the remaining 171 samples containing less 
than 2^% salt were scored off 3.54 points on an average; a 
difference in favor of the keeping quahty of high-salted butter 
of 1.16 points. Most American markets demand a salt-content 
of about 2^,*^ in the finished product. 

Salt Facilitates the Removal of Buttermilk. — That salt 
facilitates the removal of buttermilk can easily be demon- 
strated by observing the escape of buttermilk from the butter 
immediately after the salt has been added and mixed ^^dth the 
butter. The first effect of salt when added to the butter is to 
precipitate the curd in the iDuttermilk. This precipitation is 
greater when a large amount of salt is added than when only 
a small amoimt is added. The precipitation of the casein in 
the buttermilk sets free the remainder of the buttermilk con- 
stituents; that is, when the casein is precipitated, the w^hey 
part assumes a more fluid condition and escapes, and the butter 
retains a portion of the curd. Owing to this action of the 
salt, it is essential that the butter should be as complete^ 
washed as possible, as otherwise it vdH retain an excessive 
amount of curd. The butter acts in a manner somewhat 
similar to a filter in removing a part of the curd from the other 
buttermilk constituents. 

Salt in Relation to Water in Butter. — Experiment has dem- 
onstrated that pure fat is not a salt-dissoMng substance. 
Owing to this fact the only salt-dissohdng substance in butter 
is water. As water \\ill hold only a certain amount of salt 
in solution, it becomes e^ddent that the amount of salt w^hich 



260 



BUTTER-MAKING. 



can be properly incorporated in butter depends upon the amount 
of moisture present. 

The amount of salt which water will hold in solution at 
different temperatures varies somewhat according to differ- 
ent investigators. According to Gerlach * water will dissolve 
35.94% salt at 58° F. This is approximately the temperature 
at which salt is worked into butter. Theoretically, butter 
containing 15% of water should be able to properly dissolve 
5.4% of salt. Butter containing 13% of water should be able 




Fig. 154. — Action of salt solutions of different strength on the proteids of 
buttermilk. (Bui. 263, Gen., N. Y.) 

to properly dissolve 4.68% of salt, and butter containing 10% 
of water should be able to dissolve properly 3.6% of salt, etc. 
According to experiments conducted at the Iowa Experiment 
Station the maximum per cent of pure salt (NaCl) that could 
be properly dissolved in water of butter containing 16.92% 
of moisture, when worked 18 revolutions at intervals during 
two hours, was 16.57%. When butter was worked the same 
number of revolutions at intervals, and was allowed to dissolve 

* Kemiker-Kalender, p. 219. 



SALTING AND WORKING OF BUTTER. 261 

only one hour, the amount of pure salt (NaCl) that was dissolved 
in the water of the butter containing 11.58% moisture was 
14.09%. This undoubtedly will vary with different brands 
of salt. 

It will thus be seen that the property of water to take up 
salt is seemingly lessened when the water is present in a state 
of minute division, as it is in butter. In the first instance 
quoted the butter completely dissolved about 2.7% of pure 




Fig. 155. — Volumes of the same weight of salt of various brands. 
(Bui. 74, Wis.) 

salt; and in the second instance it dissolved only about 2% 
during one hour. 

Condition of Salt when Added. — The condition of salt when 
added is a very important question to consider in order to get 
enough salt properly incorporated. The amount of influence 
which the quahty of the salt has upon flavor has recently been 
a subject of attractive interest, for many of our best butter- 
judges have made the charge that certain undesirable flavors 
in butter can be traced to the use of a poor quaUty of salt. 
This assumed effect upon the quaUty of the butter can only 
be remedied by stopping the use of impure salt. The chief 
undesirable and impure constituent present in salt is magne- 



262 BUTTER-MAKING. 

slum chloride. It is known positively that the presence of this 
substance in salt, even to a small extent, imparts a bitter flavor 
to butter. Salt containing a large amount of this and other 
impurities also absorbs moisture from the air more readily 
than does pure salt. According * to analysis of the best dairy 
salt in use in Denmark, the composition is as follows: 

Pure salt 97.49 

Magnesium chloride 18 

Gypsum 05 

Sodium sulphate 21 

Water 2.07 



100.00 



The purest American dairy salt has the following composi- 
tion : t 

Pure salt (NaCl) 99. 18 

Magnesium chloride (MgCl2) 05 

Gypsum (calcium sulphate, CaS04) , -54 , 

Calcium chloride (CaCl2) 19 

Insoluble matter 03 

Moisture 01 



100.00 



In order to judge the quality of salt the butter-maker 
cannot rely on the chemical analysis for a detection of im- 
purities, but must judge the quality from its appearance, 
flavor, and odor. Good dairy salt does not have a dark-bluish, 
coarse, granulated appearance, but a clean, white, silky look, 
and should dissolve quickly. Salt should be kept in a clean 
dry place free from odor. 



* B(")ggild, Maolkeribruget, Denmark. 
t Bui. No. 74, Wis., by F. W. WoU. 



SALTING AND WORKING OF BUTTER. 263 

Gritty Butter. — "Gritty butter" is a familiar phrase used 
by expert butter-scorers to indicate that part of the salt is 
present in an undissolved condition. To most consumers this 
condition of the salt in butter is objectionable. When properly 
incorporated, salt should be present in the form of a solution 
in the butter. The gritty condition of the salt in butter may 
be due to (1) poor condition of the salt before it is added to 
the butter; (2) adding so much salt that it cannot be dis- 
solved by the water in the butter. The maximum amount 
of salt that butter will dissolve depends upon the amount of 
moisture present. The maximum amount of moisture per- 
missible in butter, as limited by law, is 16%. The condition 
of the water in butter prevents the water from being saturated 
with salt during the comparatively short time allowed for salt 
to dissolve during the manufacture of butter. (3) Insufficient 
working. If the butter is not worked enough to distribute 
the salt evenly, some portion of the butter will contain more 
than the other portions. The portion that contains the excess 
of salt does not have enough moisture to dissolve the salt; 
while if the salt had been evenly distributed in the butter, all 
the salt would have been properly dissolved. When gritty 
butter is caused by insufficient v/orking, it usually mottles. 

Mottled Butter. — ^Mottled butter is butter which is uneven 
in color. This unevenness in color may be due to several 
different causes. It may be due to specks of curd (speckled 
butter), and it may be due to certain organisms (dappled 
butter). These causes of mottled butter are not very com- 
mon in factories where the manufacture of butter is properly 
carried on. 

The most common fault of mottled butter is the improper 
incorporation of salt and the presence of an excessive amount 
of buttermilk. Mottled butter caused in this way is com- 
mon. It would be of much commercial importance if it were 
possible to prevent its occurrence. In case all the water 
had been saturated with salt, and there is still undissolved 
salt left, then the granular or undissolved salt will cause no 



264 BUTTER-MAKING. 

mottles. The most important thing to observe in order to 
prevent mottles is: (1) to have the buttermilk well washed 
out; (2) to have the salt thoroughly dissolved; and (3) to 
have the brine properly distributed. 

Recent work by Drs. Van Slyke and Hart show that if the 
proteids are thoroughly washed from the butter, mottles cannot 
be produced, no matter how unevenly the salt is distributed. 
Complete removal of the buttermilk by washing is one of the 
essentials in order to prevent mottles in butter. 

The mottles caused by improper incorporation of salt assume 
two different forms, viz., mottles proper, and wavy butter. 
As has been mentioned before, the mottles result from un- 
dissolved salt. Whenever there is undissolved granular salt 
present, the moisture is attracted and the color deepened at 
that particular place. In case the water has already been 
saturated with salt, there is no danger of mottles, no matter 
how much gritty salt is present. 

Wavy butter is caused by an uneven distribution of the 
brine. If a little salt is added to the butter and dissolved 
without working the butter sufficiently, the salt will go into 
solution in certain portions of the water. This water contain- 
ing the greatest amount of salt will produce a high color in 
certain portions of the butter, while the portion containing 
water with less salt will have a lighter color, thus causing 
streaks in the butter. 

In case butter has become mottled on standing, the mottles 
can be entirely eradicated by reworking the butter. Though 
some of the moisture is lost during this reworking process, 
it is usually advisable to rework the butter rather than to 
place it on the market in a badly mottled condition. The 
mottles should, however, be prevented rather than cured. 
This can be done by sufficient working while the butter is in 
proper condition, and at the proper time. 

Brine-salting. — Brine-salting is not as a rule practiced in 
creameries. It is too expensive a method of salting, and also 
too laborious. By salting butter with brine it is hardly possible 



SALTING AND WORKING OF BUTTER. 265 

to get in salt enough to suit the American butter markets, 
2% being about the maximum amount of salt that can be 
incorporated by the brine method. 

In some instances, brine-salting has been recommended. If 
a light mild taste is desired, the brine method may give good 
results. The greatest advantages of brine-salting are that 
mottles in butter are practically avoided, and that the over- 
run is usually increased a trifle. Especially is this so if the 
temperature of the brine is medium high when added to the 
butter. In order to get enough salt (2%) into the butter by 
the brine method, it is necessary to churn it considerably in 
the brine and to use two sets of brine. When brine is first 
added the butter already contains considerable water. This 
water practically has to be replaced by brine. This is difficult 
to do, especially if the butter has been overchurned a trifle. 

By churning the butter in the first set of brine, the brine 
will soon become diluted to such an extent that it will impart 
but little saltiness to the butter. For this reason this first 
set of brine should be removed and another one added. Then 
churn again in this brine. This last set of brine will have 
very little curd in it, and can be saved until the following day 
and then used as the first set of brine. This first set of brine 
may be used each day for soaking tubs. 

It is essential to leave the brine on the butter for from five 
to fifteen minutes. Churning excessively in the brine, espe- 
cially if butter is medium soft, will cause too much water to 
be incorporated in the butter. After the butter has been ex- 
posed to the second set of brine the proper length of time, it 
should be drawn off and the butter worked in the usual manner. 
Less working is usually given to butter which has been salted 
by the brine method. It should be worked enough to dis- 
tribute the brine evenly in the butter, and to bring the butter 
into a compact form. If the butter salted by the brine method 
is not worked sufficiently, it will after standing become streaky 
in color. 



266 BUTTER-MAKING. 



Working of Buttei?. 



Objects. — The objects of working butter are: 

(1) To distribute the salt and brine evenly in the butter. 
The number of revolutions in the churn necessary to accom- 
])lish this will vary somewhat according to the conditions of 
the butter, and according to the kind of butter-workers em- 
ployed. If the butter is of medium firmness, about 12 revolu- 
tions in the Victor Combined Churn will usually distribute the 
salt properly, providing the working is well distributed over the 
working period. It used to be, and is still, the practice in 
creameries to add the salt while the butter is in a hard granular 
condition, and then rotate the churn several times in slow gear 
without putting the workers in gear. This is done in order 
to mix the salt thoroughly without working. Then it is allowed 
to stand for five or ten minutes, then worked about four revolu- 
tions and allowed to stand a little while again, then the working 
is completed by allowing the churn to revolve four or five times 
more, or as many as is deemed necessary to bring the butter into 
proper condition. 

It has, however, been demonstrated that it is not advisable 
to add the salt while the butter is in this hard granular form. 
The butter should be united into larger irregular granules before 
the salt is added. If the salt is added to the butter in a more 
or less gathered condition, then the workers should be put in 
gear at once, for otherwise the salt will be scattered on the 
inside of the churn. Butter can be worked three or four revolu- 
tions and then allowed to stand until the salt is almost dissolved, 
at which time the working can be completed by revolving 
the churn four or five revolutions more. Some prefer to work 
a little more than ten revolutions in order to be sure that the 
salt has been evenly distributed. 

If the Disbrow churn is being used, it is necessary to work 
the butter a greater number of revolutions than that recom- 
mended when the Victor churn is used. In the Victor churn 



SALTING AND WORKING OF BUTTER. 



267 



the butter is virtually worked twice at every revolution, while 
in the Disbrow churn the butter is only worked once for about 
three-quarters of a revolution. From sixteen to twenty revolu- 
tions of the Disbrow churn usually mixes the salt with the butter 
properly. It is impossible to state exactly the number of revo- 
lutions butter should be worked, as it varies according to differ- 
ent conditions. 

(2) Working the butter is done in order to bring it into a 
compact form. When butter is soft it usually gathers, but 




Fig. 156. — The table butter-worker. 



if it is present in the firm granular condition, which condition 
results from churning thin cream and washing the butter in 
cold water, it is more or less difficult to get the little granules 
together. More working is necessary when the butter is in 
such a condition. 

(3) The working of butter is also done in order to express 
an excessive amount of buttermilk or water. By adding salt 



268 BUTTER-MAKING. 

and then working the butter, the excess of buttermilk is largely 
eliminated. Especially is this so when the butter is in a medium 
firm condition. Working is also effective in removing water 
from the butter. 

In the manufacture of process butter, excessive working 
while the butter is in a firm condition is now resorted to. 
Before the national law, which limits the moisture- content of 
butter to 16%, went into effect, process butter usually con- 
tained more than 16% water; but now the moisture-content 
of this kind of butter is largely controlled by working it in the 
absence of water while it is in a firm condition. 



CHAPTER XVIII. 

PACKING AND MARKETING BUTTER. 

Kind of Package to Use. — For creamery purposes the 60- 
pound ash tubs are customarily used. The package, of course, 
varies according to different markets. In case that butter is 
made on a small scale, such as on the farm, earthen crocks give 
good satisfaction. There is no other package that gives so 
good results as the earthen jars, when viewed from a stand- 
point of good keeping quality of the butter. The objec- 
tion to earthen jars or crocks is that they are heavy and easily 
broken during transportation. It is undoubtedly on this 
account that earthenware is not used more for the packing of 
butter. 

There are two kinds of tubs chiefly used in creameries, viz., 
the ash tub, and the spruce tubs. These tubs are made in 
different sizes, 10-lb., 20-lb., 30-lb., and 60-lb. The 60-lb. 
ash tub is used nearly altogether in creameries that pack butter 
on a large scale. When smaller amounts of butter are being 
packed, usually the smaller spruce tubs are employed. Square 
boxes are used also to some extent. They are used more in 
some of the Eastern States, but very little in the AA^est and 
Central AA'est. 

During the fall and winter when the milk-supply is rather 
low, many creameries print all the butter. Most of the com- 
mission firms will pa}^ about a cent more per pound for butter 
when it is put up in pound prints and wrapped neatly in parch- 
ment paper. The wrapper should bear the name of the manu- 
factm-er or the name of the creamery. If the quahty of the 

269 








^^ ^ j^-^-~,atet^~- ^ te; 




PACKING AND MARKETING BUTTER. 271 

butter is good, it will take but a short time for the consumers 
to become familiar with that particular brand. It is essential, 
however, to consider the cost of printing the butter and the 
losses in printing. Some little waste of butter accompanies 
the printing process. Besides this, if the butter is firm, as it 
usually is in order to have the prints assume the proper shape, 
there is a loss of some moisture. 

Preparation of Tubs. — If tubs are stored in a damp room, 
they are likely to mould in a short time. Occasionally tubs 
are in a mouldy condition when they come from the factory 
or creamery supply-house. The mould that forms on the inside 
of the tub when standing in a damp place is very conspicuous. 
In many instances the tubs are also cracked. This is due 
chiefly to the tubs becoming dry, and in some instances is due 
to the use of imperfect material in the manufacture of the tub. 
Butter-tubs should not be made from damp, unseasoned, and 
partly decayed wood, as they are likely to impart to the butter 
more of the woody odors than do those made from sound, 
well-matured wood. 

In order to kill all the moulds which may be present in the 
tub, and to close the cracks, so as to make the tub practically 
air-tight, it is essential that the tub should undergo some process 
of preparation before the butter is packed into it. There is a 
single substance which will destroy the germs, moulds, and also 
close smaller openings in the tubs, viz., a saturated solution of 
brine. As a rule this gives good results. The day previous to 
the packing of the butter, the tubs should be filled with satu- 
rated brine, and allowed to stand and soak until the following 
day. The paper-linings and circles should also be soaked in 
the same brine before they are used. It is a good plan to have 
the brine lukewarm, although cold brine will answer the pur- 
pose. Just pre\dous to using, pour out the brine, wash the tubs 
thoroughly, then scald them, by putting them into scalding- 
hot water or over a steam-jet. Cool off the tubs by filling them 
with cold water; when cooled, pour out the water, line them, 
and they are ready for use. The covers should be on while they 



272 



BUTTER-MAKING. 



are soaking. This prevents the tubs from warping and getting 
out of shape. 

By soaking the tubs in brine and scalding as above, if 
thorouglily done, there is little danger of getting moulds in 
the butter. Some recommend the soaking of the tubs in brine 
only, without scalding; others recommend the scalding without 
soaking in brine. The cliief difficulty with scalding the tubs 





-Elgin style butter- 
tub. 



Fig. 159.— Bradley 
butter-boxes. 



without soaking is that when wooden tubs are exposed to such 
sudden heat they usually warp. The hoops are also likely to 
burst, and if this method is employed alone, many of the tubs 
will be rendered valueless owing to the bursting of the hoops. 
If the tub is gradually soaked in brine first, heat may be applied 
afterwards with little or no injury to the tub. Owing to the 
many complaints of mouldy butter, especially during the 
summer, several other methods of preparing tubs have been 
recommended. In following out the above method many makers 



PACKING AND MARKETING BUTTER. 273 

omit to use concentrated brine. If the brine is weak, then, of 
course, it will have httle or no effect upon the moulds; but 
if the brine is saturated, the wood will become saturated with 
brine and prevent the growth of mould during the trans- 
portation of the butter. Moulds usually start to grow on the 
inside of the tub, next to the butter. 

Some of the other methods recommended for the prepara- 
tion of tubs are: (1) Paraffining. This is accomplished by- 
melting the paraffin, then using a soft brush with which to 
spread the liquid paraffin all over the inside of the tub. After 
the hquid paraffin has been applied and cooled, it will solidify, 
and a thin layer of paraffin will cover the inside of the tub. 
(2) The second method is to soak the tubs in brine containing 
from 2% to 3% of formalin (40% formaldehyde solution); 
about three ounces of formalin to each gallon of brine is about 
the proper proportion. 

Special efforts should be made towards having the package 
appear as neat as possible. They should be clean, and the cover 
should fit well. After the tub has been washed, lined, and 
otherwise prepared, it should be weighed, and the weight of the 
tub marked on the outside. 

Packing of Butter.— The packing of butter should be con- 
ducted under as favorable conditions as possible. Before mak- 
ing use of the butter-ladles they should be scalded and then 
cooled off in cold water. This prevents the butter from sticking 
to them, and also cleanses them from dust and germs which 
may have lodged on them. When the butter is being transferred 
from the churn into the tub, it should be firmly packed. That 
is, there should be no holes near the bottom and sides of the 
butter in the tub. When the butter arrives on the market 
it is sometimes turned out of the tub (stripped). If it has 
not been firmly packed, the butter will be filled with holes 
on the sides and show an unattractive appearance. Besides 
this, if there are any holes in the butter, the moisture and air 
will gather there. This gathered brine at time causes a change 
in color on the surface of the butter to which the brine was 



274 



B UTTER-MAKING. 



exposed. The tubs should be well filled. Any open spaces 
left in the butter permit the circulation of air, and the butter 
is more likely to absorb the woody odors from the tub. 





Fig. 160.- 



-The Eureka butter- 
printer. 



Fig. 



Folded. 
161. — Butter cartons. 



In the preparation of the tubs, many of these woody odors 
are eliminated, but it is impossible to remove all of them. The 
heat when applied to the tub opens up the pores of the wood 
and causes the volatile woody odors to pass off with the escaping 
steam. When the wood is removed from the influence of the 
steam, the pores again close, or contract, and in that way most 
of the woody odors are removed, at least from the inner surface 
of the tub. The remaining woody odors should not be allowed 
to circulate inwardly through the butter by allowing empty 
spaces inside the tub. The top surface of the butter can 
be made to appear smooth and full by filling the tub a little 
more than full of butter, and then cutting the excessive amount 
of butter off with a string. The extra butter can then be rolled 
off, and the top appear perfectly smooth and full. 



PACKING AND MARKETING BUTTER. 



275 



The surface of the tubs should be neatly finished by pleating 
the lining of the tub over onto the top of the butter. The 
lining should not be ahowed to lap over any more than about 
an inch. A cloth circle should then be neatly put on. A 




Fig. 162. — Tub-fasteners; common tins. 

handful of salt sprinkled on the top of this circle is advisable. 
A little water may be sprinkled on to cause the salt to become 
wet. Some butter-makers prefer an additional paper circle 
on top of the salt again. 




Fig. 163. — Tub-fasteners; tin and tack combined. 

Packing Butter for Exhibition Purposes.— -In case butter is 

to be opened and scored several times, it is advisable to use paper 

circles instead of cloth circles. Cloth circles give a much better 

appearance when the tubs are not to be opened often, but they 




Fig. 164. — Tub-fasteners; riveted, 
are difficult to readjust after they have been taken out of posi 
tion, while the paper circle can be taken off and replaced as 
often as desired. This apphes especially to butter entered 
for scoring contests, where the keeping quafity of butter has 
to be tested also. Twenty-pound ash tubs are generally used 
for exhibition purposes. Ash tubs take a little better finish 



276 BUTTER-MAKING. 

than do spruce tubs. Sandpapering the tubs on the outside 
gives a nice appearance. A fine-appearing tub may count con- 
siderably when the final decision is rendered. In order to keep 
the tub in a clean and good condition during transit special 
precautions should be taken by the sender. A good way of 
preparing a tub is to tack the address on the cover, wrap the 
tub well in paper, and fasten the paper by wrapping a string 
around the tub a few times. Drive no more nails in the tub 
than is necessary. Three tins are sufficient to fasten the 
cover to the tub. The tin fasteners should be placed equal 
distances apart. After the paper has been wrapped around 



Fig. 165. — The Lafayette lever butter-printer. 

the tub the whole should be burlapped. These burlaps can 
be obtained with the tubs from any of the creamery supply- 
houses. The tub should then be labeled, and it is ready for 
shipment. 

Another good way of preparing a tub for shipment is to 
pack the 20-pound tub into a 60-pound tub. Fill the space 
between the small and the large tub with paper. This is con- 
sidered by many to be the best method of shipping butter for 
contests, as the paper, packed in on the sides of the tub, pre- 
vents the heat from penetrating. In cold weather it also pre- 
vents the butter from freezing, at least in a measure. 

Storing Butter in Creameries. — The temperature of the 
room in which the butter is being stored should be as low 
as conditions will permit. A temperature of 50° F. or below 
is favorable to the keeping quality of the butter. Usually the 



PACKING AND MARKETING BUTTER. 



277 



butter is kept at the creamery for from half a week to a whole 
week. It is advisable to ship as often as is considered con- 
sistent mth the amounts of butter handled. The refrigerator 
in which the butter is kept at the creamery should be kept 
as pure and dry as possible. Damp places are always con- 
ducive to the growth of germs, especially moulds. Vegetables 
or foods of other kinds should not be allowed in the refrigerator 




Fig. 166. — The engine-room of Littleton Creamery Co. (Creamery Journal.) 

with the butter, as they are likely to impart foreign flavors to 
the butter. Mechanical refrigeration and cooling with ice are 
the best cooling facilities. In case it should happen that it is- 
impossible to obtain ice, water can be utilized for this purpose. 
The water used in the creamery can be made to run through. 
a galvanized-iron tank. This tank is properly placed in the 
butter storing-room, or refrigerator, so as to allow as much 
cooling-surface in the butter-room as possible. This method 



278 



BUTTER-MAKING. 



will not cool the room as effectively as ice, but in the absence 
of ice this is better than no cooling at all. 

Cost of Producing One Pound of Butter. — The cost of pro- 
ducing a pound of butter varies at different creameries. Up 
to a certain limit, the more butter that is being produced at 



Dead Air Space 




Fig. 167. — Cross-section of a sewage-disposal tank. (Wallace's Farmer.) 

one place the less will be the cost of production, that is, pro- 
vitUng the creameries are otherwise equally well managed. 
The Iowa State Dairy Commissioner has investigated this 



Ground 



J;L"e 




Fig. 168. — Septic tank for creamery sewage disposal. (By Prof. J. Michels.) 
The tank should be located in the ground with the top within a foot or 
two of the surface. It may be constructed of planks. Brick, stone, or 
concrete is preferable for durability. The tank should be built air- 
tight except in two places, D and E. 

question and finds that the cost of production varies from 
1.2 cents to 6 cents per pound. According to the reports sub- 
mitted to the office of the State Dairy Commissioner, the 
highest cost of production conies from a co-operative creamery 
that makes a little less than 30,000 pounds of butter per year. 
The lowest cost of production is submitted by a co-operative 



PACKING AND MARKETING BUTTER. 



279 




280 



BUTTER-MAKING. 



creamery making nearly half a million pounds of butter from 
whole milk exclusively. The approximate average cost of mak- 
ing butter for the whole State of Iowa in the whole-milk cream- 
eries is about 2\ cents per pound. As the creameries produce 
on an average about 150,000 pounds of butter per year, the 
running expenses of the average creamery are approximately 
$2350.00 per year. 

The following table will show the variation in cost of pro- 
duction per pound of butter : 



Class. 



Creamery Cost of Manufacturing a Pound of Butter. 

Creameries making no more than 50,000 lbs. of 

butter 

Creameries making between 50,000 and 100,000 

lbs. of butter 

Creameries making between 100,000 and 150,000 

lbs. of butter 

Creameries making between 150,000 and 200,000 

lbs. of butter 

Creameries making between 200,000 and 300,000 

lbs. of butter 

Average for the State 

Avera<j;e for classes 2 and .3 



No. 
Reported. 



44 
98 
56 

28 
27 



253 
154 



Cost, 

Cents. 



3.14 
2.36 
1.99 
1.78 
1.71 



2.28 
2.22 



CHAPTER XIX. 

COMPOSITION OF BUTTER. 

Butter is composed of fat, water, proteids, milk-sugar, 
ash, and salt. The milk-sugar and ash are present in butter 
onhT- to a very small extent. In the analysis of butter the 
milk-sugar is usually included with the proteids (curd), and 
the ash is reckoned in with the salt. 

Storch gives the following average composition of butter: 

From From 

Fresh Cream. Ripened Cream. 

Fat 83.75 82.97 

Water 13.03 13.78 

Proteids (curd) 64 .84 

Milk-sugar 35 .39 

Ash 14 .16 

Salt 2.09 1.86 

The average composition of butter as determined from the 
analysis of 221 samples, representing 55 different creameries 
in different parts of the State of Iowa, is as follows : 

Fat 84 

Water 12.73 

Curd 1.30 

Salt and ash 1 .97 

Effect of Composition of Butter Upon Quality. 

The quality of cream or milk from which the butter has been 
produced and the methods employed in the manufacture have 
more effect upon the quality of butter than has the composi- 

281 



282 ;>• ITT /•; R- .1 / - 1 K INC. 

tion. A small variaCutn in {\\c vowxponents of buttor atTocts 
the (|iiality \(M'y liltlc, |)r(ni(l(vl the buttor has boon ])r()p(n'ly 
made, and th(> compitnents pi-opcMiy incorporatcnl. In the 
same ci'eanuM'y tlu> composition of butter varies aecorilini:; to 
th(> s(\ison o( {\\v year, from day to day, and even from one 
ehurnini!; to anothcM". Aceordini;' to th(> jirc^scMit methods ot 
maiuil'aetui-(\ watvr. salt, and t'at are th{> ('om|)on(Mds most 
lik(>ly to \ary. Casinn Naries very little. 

Curd and Sugar. Oeeasionally the curd eont(Mit ma\' i;'o as 
high as I', . It rarely c^xceeds L*'',,, and soldom falls beUnv .5 
of 1%. A high cnrd-eontent will show its(>lf in the butter in 
the foi"m of a milky brino, or in tho form of white speeks. II 
tliert> is l(>ss than '_" , o.' eui'd pri>sent in tin* buttca-, tlu> brine 
shows no noticeable milkiness. Mori^ than that nmch curd 
can, as a rule, \)c d(>tect(Hl from the coUn- of the brin(\ 

If tlu> casein ov the curd has been incoi'poratrd in tlu^ form 
o\' small luni|)s or s])c>cks, then abnoi'mal amitunts of curd 
appear. When the saniph^ (^( buttiM- is taken for analysis, such 
a sp(H'k (^{ curd pres(>nt in tlu> sampK^ rais(>s the hnal curd-eon- 
tent to a compai'atix'ely high ligure. 

As has b(>en mentioninl b(>fori\ [\\c curd and milk-sugar are 
incorporatinl from th(> buttermilk into tlu> butter dui-ing tlu> 
churning. In manufacturing butter for storage, tlu^se sub- 
stances shouUl bc> e\clud(>d from tlu^ butter as thoroughly as 
possibl(\ 'Vhv milk-sugai' and albuminoids constitute the chief 
food for bacterial growth. .Vs {\\o d(>t(Mioration of butter lias 
beiMi d(Mnonstrat(>d to be due t*hi(>lly to tlu> action of organisms, 
it InH'tMtus i>ss(>ntial to restrain tlu>ii' growth as nuich as possible 
by excluding food necessary for their growth. 

Salt. — In the chapter iliscussing the salting of butter, it was 
mentioned that a small increase or d(H'n\ise in the salt-content 
of butter can be rtH'ognized by most consumers, while the same 
variation in the other cimstituents cannot be noticed so easily. 
The average salt-contcMit of butter is about 2%. As the amount 
of salt properly dissolved in butter depends upon the amount 
of water present, the first important step in controlling the salt- 



COMPOSITION OF nUTTMR. 



283 



contcuit irt to have reusoiuiblc! control of the water- content of 
the biitt(>r. If there is no more than 16% of water present in 
the butter, it is desirable to have as much salt in as the water 
will dissolve within the time usually allotted for that pui'pose. 
This much salt suits most of the 
American butter markets. The 
authors have analyzied commercial 
butter containing more than 8% salt. 
The major poi-tion of this was present 
in an undissolved coiKhtion. Sucli 
butter is called gritty, and is ob- 
jected to by most consumer's. 

Salt acts as a preservative and 
adds flavor to the butter, provided 
it is in good condition. It is said 
that th(^ ad(htion of salt has some 
effects upon the body of the l)Utter. 
Richmond asserts that salty butter 
loses mon; wat(u- on standing than 
unsalted l)utter. This is undoubt- 
edly due to the leaky condition which is brought about when 
salt is added to butter while in a granular condition. Salt 
attracts moisture. Unsalted butter would not be exposcnl to 
this in(luenc(; of the salt. When ke[)t unsalt(!d, l)utter usually 
becomes cheesy in flavor in a short tinu;, whih^ salt(;d butter 
assumes entirely diU'erent characteristics. 

Water.— The moisture-content of butter may vary b(^tween 
6% and 16%. Frequently butter is found tliat contains more 
than 16%, but this amount is in violation of the law. Butter 
may contain as much as 18% of water, if properly incorporated, 
witliout affecting its ai)p:u'ent coinmerci;d (junlity. Water is 
present in a greater proportion than any other non-fat con- 
stituent. Its variation is also greater than that of any other 
constituent. The fat will, of (course, vary with the water. 
The more water there is present in the butter, the less fat tliere 
will be, and the less water, the more fat. As butter is bought 




I'K;. 170. — lc.e-(;iii,sl)ur. 



284 BUTTER-MAKING. 

with the understanding that it is rich in fat, much objection has 
been raised to butter containing an abnormal amount of water. 
This objection by consumers is, of course, a just one. The 
producers desire to incorporate as much water as is consistent 
with good quality. Butter containing a high moisture- con- 
tent, more than 18%, will appear dead and dull. It is sticky, 
and when sampled with a trier it is next to impossible to draw a 
full trier of butter. It shrivels and rolls on both sides of the trier" 

Moisture affects Ixitter in two principal ways, according to 
the way in which is is incorporated: (1) By causing leaky 
butter, and (2) by making the butter appear dull. 

1. This leaky condition in commercial butter is very common. 
It has been a common opinion among butter- judges that w^hen- 
ever water appears in large drops on the butter, and some- 
what slushy when sampled, the butter contains too mucli 
moisture. This, however, is not always the case, as butter will 
not as a rule hold an excessive amount of moisture in that form. 
Even if this leaky butter does not contain an excess of moisture, 
it is a very undesirable condition, as most consumers object 
to this apparent slushiness. As has been stated before, this 
leaky condition is brought about chiefly by churning the butter 
to small granules, washing the butter very little in cold water, 
salting heavily, while butter granules are still small and firm, 
and working the butter frequently in the presence of brine. 
When moisture is properly incorporated in butter, it should 
be present in exceedingly minute drops. In a fine state of 
division it will not escape from the butter. 

This leaky condition of moisture in butter may give a wrong 
impression to consumers about its moisture- content. Major 
Alvord, Chief of Dairy Division of U. S. Department of Agri- 
culture, reports that a great many buyers on the English market 
have the opinion that American butter contains an excess of 
moisture. This conclusion evidently has been reached on 
account of the water in American butter often appearing in 
this leaky condition, as described above. In reality it is low 
in its moisture-content. 



COMPOSITION OF BUTTER. 285 

2. The dull and dry appearing condition of butter may be 
due (1) to the presence of an excess of moisture properly incor- 
porated; (2) to the treatment the butter receives during manu- 
facture. When the dull and dry appearance is due to moisture, 
the water has been incorporated during the churning, or during 
the washing process, through excessive churning or working 




Fig. 171. — Rubber mop. 

in the buttermilk or wash-water at a high temperature. The 
dullness may also be brought about by overworking the butter. 
If the butter has been overworked, as a rule, it contains little 
moisture, though its appearance may be like that of butter 
containing an excess. 

The conditions which affect the moisture-content of butter 
during its manufacture are: 

(1) Temperature of cream and of wash-water. The higher 
the temperature of these two substances, the more water will 
be incorporated in the butter. When the temperature is too 
high, the body of the butter is injured materially. The keeping 
quality of the butter is also injured by having the temperature 
of the cream too high. The buttermilk constituents are incor- 
porated with the butter and cause it to deteriorate rapidly. 

(2) The amount of churning in buttermilk and wash-water. 
The more the butter is being churned or worked in the presence 
of moisture, the more water the butter will contain. When the 
temperature of buttermilk and wash-water is low, a small 
amount of churning affects the moisture-content very little, 
while if the temperature is high, great care should be taken 
not to overchurn. 

(3) Per cent of fat in cream. The thicker the cream the 
more moisture there will be present in the butter. In order to 



286 BUTTER-MAKING. 

churn thick cream, a higher temperature is necessary. It is 
difficult to stop the churn without overchurning a trifle. These 
two conditions, thick cream and high temperature, are both 
conducive to a higher moisture- content. 

(4) Amount of work the butter receives. If the butter is 
in a moderately firm condition, the more the butter is worked, 
in the absence of water, the less moisture it will contain. If 
the moisture is present in a leaky form as mentioned above, it 
is expelled to a great extent by working. But if the moisture 
is properly incorporated and the butter is not too firm, work- 
ing has little effect upon changing the moisture-content of the 
butter, providing there is no water present in the churn. 

Several other factors, such as pasteurization of cream, full- 
ness of churn, and character of fat in cream, all have a small 
influence in governing the moisture-content of butter, but in 
this summary it is sufficient to say that temperature, degree 
of churning, and thickness of cream are the only conditions 
which materially influence the moisture- content. If churning 
is carried on to an excess, whether it be in the buttermilk or 
in the wash-water, all other factors are subordinate and have 
little or no influence in regulating the moisture-content of 
butter. Low temperature is the chief factor that delays in- 
corporation of moisture in excessive churning. 

Fat. — The English, the German, and the United States 
governments have endeavored to protect consumers in regard 
to the amount of nutriment in butter, by recommending 16% 
of water as a maximum limit. Such a ruling has worked suc- 
cessfully now for several years. Efforts have recently been 
made in the United States to base by law the nutritive quality 
of butter upon a certain minimum percentage of fat. The 
minimum amount of fat recommended by the appointed com- 
mittee of chemists is 82^%. A minimum standard of 82 J% 
of fat in butter would be unintentionally violated, while a basis 
of 80% fat in butter would be more consistent with the quality 
of butter as manufactured. 



CHAPTER XX. 

JUDGING AND GRADING BUTTER. 

Butter may be judged from a commercial and from an 
individual standpoint. Individual judgments of the same 
butter may vary considerably. It is important that the judge 
should become familiar with the quality of butter as required 
by our standard markets, and then judge the butter according 
to the demands of the mass of the consumers, rather than 
according to personal likes and dishkes. In order to become 
a good butter-judge, it is essential that the senses of taste and 
smell be acute. Even if one's taste and smell are keen and sensi- 
tive, considerable practice or experience is necessary. Almost 
any one can tell a good sample of butter from a very poor one, 
but when it comes to differentiate between two samples wliich 
are nearly alike in quality, skill and experience are required. 

The chief thing in scoring butter is to become thoroughly 
familiar with the ideal flavor of butter; then by repeated 
comparisons of different samples of butter to tliis one ideal 
flavor, one will soon become efficient in grading the butter. 

Standard for Judging. — In America the distinct quahties 
which are noticed in butter are designated according to the 
basis of points given below. It will be noticed that different 
values are given to the different characteristics, according to 
their relative importance. The score-card given below is used 
commercially, and is based upon 100 as perfect: 

Score-card. 
No 

Perfect. Score. Remarks. 

Flavor 45 

Body 25 

Colo"!- 15 

Salt 10 

Style 5 

Total 100 

Date Scored by 

287 



288 BUTTER-MAKING. 

At a recent conference of the Societe Nationale de Laiterie, 
held at Brussels, the following scale of points was suggested for 
butter (Creamery Journal) : 



Odor 5 

[ Color 5 

I Reflection 10 

I Cleanliness 5 

[ Chemical analysis 10 

f Firmness 13 

Consistency \ Spreading facility 12 

[ Interior structure 5 

/ Purity 5 

\ Taste and aroma 30 

TckT 



Work. 



Taste. 



Score-card used by W. S. Moore & Co., Chicago. 

Stencil Date 

Creamery 

Buttermaker 



Too high acid 1-3 

Sour 1-3 

Heated 9 

Weedy 2-10. .. 

Tainted 2 

Barny 2-10 . . . 

Poor sewerage, dirty cans, etc 5-10. . . 

Wintery 2-10. . . 

Old milk 2 

Flat 1-3 ... . 

Light 1-3.. .. 

Summery 1-10 . . . 

Needs more acid 1-3 . . . . 

Poor water or ice 

Fishy 4-6 

Cowy. . 1-2-10. 



Fine, high, clean. . 
Score (Perfect 45). 



CQ 



Weak 4.. 

Salvy 4.. 

Greasv , . . . . 4 . . . 

Oily. !' 4... 

Tallowy 4.. . 

Cheesy 4 . . . 

Loose body 4-7 , 

Too much water 4 . . . 

Not enough water 4 . . . 

Water not well incorporated 4. . . 

Milky 



Fine, waxy 

Score (Perfect 25). 



JUDGING AND GRADING BUTTER. 289 



Wavy 4-6. 

Streaked ..4-6. 

Mottled 4-6. 

Too high 

Toohght 

Not good shade 



Fine, even, light straw colored. 
Score (Perfect 15) 



Too high 6. . . 

Too light 6 . . . 

Flat 6... 

Gritty 4-6. 

Fishy 4-6. 

Poor grade of salt. . . 

Irregular. • • • • 



Fine, smooth 

Score (Perfect 10). 



Tops not neat 7 . . . 

Too much salt on tops. . 7-8 . 

Tubs not full 7. . . 

Stroke tops off level ; do not bevel 7 . . ■. 

Fold paper liners under cloth circles, not on top 

Not paper lined 

Liners poor grade 

Too much brine 7-8 . 

Loosely packed 7-8 . 

Tubs dirty 7 . . . 

Tubs muddy 9 • ■ ■ 

Tubs soaked too much 7-8 . 

Tubs mouldy 7 . . . 

Dark-colored staves 7 . . . 

Not Elgin-style tubs 7 . . . 

Tubs flimsy 7 . . . 

Broken hoops and covers 7 . . . 

Tares too light; 11 lbs. wanted 8. . . 

Tares too heavy; 11 lbs. wanted 8 . . . 

Hooks or poor tin fasteners 7 . . 



Fine, handsome. . 
Score (Perfect 5) 



Total score (Perfect 100). 



290 BUTTER-MAKING. 

Manner of Judging. 

Body. — After the trierful of butter has been drawn out, 
the first thing to notice is the aroma, and the body or texture 
of the butter. The butter on tlie outside should be examined 
at once before it is affected by the temperature of the room. 
Notice its color, whether it is even or uneven, low or high. 
Determine by the appearance of the butter and the way it feels 
to the palate whether it is greasy, tallowy, spongy, or sticky. 
The amount of brine and condition of brine should also be 
noted. These characteristics and their causes have been 
previously discussed. Stroke the plug of butter with a knife 
to observe the color closer. Squeeze it with the thumb to 
ascertain the character of the body. The aroma of the butter 
should also be noticed in connection with scoring the butter 
on body or texture, as it is more pronounced immediately after 
the trierful of butter has been drawn. 

Flavor. — It is impossible to describe all the different flavors 
found in butter. There are perhaps as many distinct butter 
flavors as there are shades of colors. However, there are a 
few flavors which stand out more prominent and are more 
commonly met with than any of the others. Good butter 
should possess a clean, mild, rich, creamy flavor, and should 
have a delicate, mild, pleasant aroma. Some butter judges, 
especially foreign judges, allow a separate number of points 
for aroma of butter in the score-card. This has been sug- 
gested in the United States also, owing to the fact that 
butter may have little aroma and still have a good flavor. 
Owing to this, it has been suggested that it would be better to 
allow a certain number of points separately for aroma in the 
score-card. 

Flat flavor is noticeable in butter made from unripened 
cream. If such butter is otherwise clean, little objection is 
made to this kind of butter for ordinary commercial purposes. 
The remedy is to ripen the cream a little higher with a proper 
ferment. Rancid flavor is applied to butter which has an 



JUDGING AND GRADING BUTTER. 291 

undesirable, strong flavor. Rancid flavor is the most common 
defect developing in butter on standing. Other flavors develop- 
ing in butter are "turpentine," "fishy," "unclean," "feverish," 
and "stale" flavors. In criticizing butter it is better to mark 
at once the specific fault, rather than state that the butter 
is rancid. Cheesy flavor is another characteristic which is very 
common in butter. This cheesy condition develops chiefly 
in butter containing little or no salt. It is claimed to be due 
to the decomposition of the proteid matter in the butter. 
Weedy flavors are quite common in butter. They are due 
mostly to the condition of milk previous to the manufacture 
of the butter. The remedy is to take the cows away from the 
pasture in which weeds of different kinds are growing, such as 
garlic, wild onions, etc. Acid flavor is another common defect 
found in butter. It is usually due to improper ripening of 
cream . The term sour is used in its literal meaning in describing 
butter which in reality is sour, though not very sour to the 
taste; by the sense of smell, however, the sourness is readily 
perceived. The usual cause of this sourness is an improper 
removal of the buttermilk before the butter is packed. The 
term sour is occasionafly used to designate butter which has 
been made from overripened cream. Feverish flavor is a 
comparatively new term. Its significance seems to be of 
importance. This flavor is very sickening. It is beheved to 
be due to the cow's system being in an unhealthy condition. 
This flavor is imparted to the butter when it is produced from 
milk drawn from cows during sexual excitement. Diarrhoea 
of the cows is claimed to produce the same effect. Stable 
flavors are due to the improper and unclean conditions of the 
barn. They are most common during the winter, when cows 
are exposed to stable conditions. 

Color. — The color should be bright and even. When a plug 
of butter is drawn with a trier and is held up to the light, it 
should not be cloudy and dense, but should be almost transparent 
and bright. The chief fault found with the color of butter 
is unevenness. It may be streaky, mottled, or it may be too 



292 BUTTER-MAKING. 

high or too low. The shade of color will vary according 
to the different markets. The color preferred in our markets 
is chiefly a high straw color. There has been a tendency re- 
cently to recommend a comparatively high color in butter, in 
order to distinguish it from oleo margarine. A reddish color, 
however, should be guarded against, except when the market 
demands it. If too much color is added, butter will assume 
this hue, which is very undesirable. 

Salt. — The amount of salt likewise depends upon the market, 
and unless the salt-content is extremely high, or extremely 
low, butter should not be criticized on account of the amount 
of salt. The chief thing to consider in judging butter on its 
salt-content is the condition of the salt. Notice whether it 
has been thoroughly dissolved and evenly distributed. 

Style. — The style is the appearance of the butter and package- 
Whatever the shape of the package, the chief thing to consider 
is that it is clean and neatly finished, as described in the para- 
graph on "Exhibition of Butter." 

Classification and Grades of Butter. 

The classification and grading of butter on the different 
markets vary very little. As the New York market is the 
great butter market in the United States, we quote the classi- 
fication and grades of butter as outlined by the New York Mer- 
cantile Exchange : 

"CLASSIFICATION. 

'' Creamery Butter. — Butter offered under this classification 
shall have been made in a creamery from cream obtained by 
the separator system, or gathered cream. 

''Imitation Creamery Butter. — Butter offered under this 
classification shall have been churned by the dairyman, col- 
lected in its unsalted, unworked condition, and worked, salted, 
and packed by the dealer, or shipper. 



JUDGING AND GRADING BUTTER. 293 

" Dairy Butter. — Butter offered under this classification shall 
be such as is made, salted, and packed by the dairyman, and 
offered in its original package. 

" Factory Butter.— Butter offered under this classification 
shall have been collected in rolls, lumps, or in whole packages, 
and reworked by the dealer, or shipper. 

" Renovated Butter. — Butter offered under this classification 
shall be made by taking pure butter and melting the same, 
and rechurning with fresh milk, cream, or skim-milk, or other 
equivalent process. 

" Grease shall consist of all grades of butter below Fourths 
free from adulteration. 

" Known Marks shall comprise such butter as is known 
to the trade under some particular mark or designation, and 
must grade as Extras, if creamery, and Firsts, if reworked 
butter, in the season in which it is offered, unless otherwise 
specified. Known Marks to be offered under the call must 
previously have been registered in a book kept by the superin- 
tendent for that purpose. 

" GRADES. 

" Grades of butter must conform to all the following re- 
quirements, and shall not be determined by the score alone. 

" Extras. 

" Extras shall be composed of the highest grades of butter 
made in the season when offered, under the different classi- 
fications; 90% shall be up to the following standard; the balance 
shall not grade below Firsts: 

" Flavor.— Must be fine, sweet, clean, and fresh, if of current 
make, and fine, sweet, and clean, if held. 

''Body. — Must be firm, smooth, and uniform, 

" Color. — A light straw shade, even and uniform. 

" Salt.— Medium salted. 

" Package. — Good, uniform, and clean. 

"Score. — Shall average 93 points, or higher. 



294 BUTTER-MAKING. 

" Firsts. 

"Firsts shall be a grade just below Extras, and must be 
fine butter for the season when made and offered, under the 
different classifications, and up to the following standard: 

" Flavor. — Must be good, sweet, clean, and fresh, if of cur- 
rent make, and good, sweet, and clean, if held. 

" Body. — Good and uniform. 

" Color. — Reasonably uniform; neither too high nor too 
light. 

" Salt.— Medium salted. 

" Packages. — Good and uniform. 

" Score. — Shall average 87 points, or higher. 

"Seconds. 

" Seconds shall be a grade j ust below Firsts, and must be 
good for the season when offered, under the different classifi- 
cations, and up to the following standard: 

" Flavor. — Must be reasonably good and sweet. 

" Body. — If creamery or dairy, must be solid boring. If 
factory or renovated, must be 90% solid boring. 

" Color. — Fairly uniform. 

" Salt. — May be high, medium, or light salted. 

" Package. — Good and uniform. 

" Score. — Shall average 80 points, or higher. 

" Thirds. 

"Thirds shall be a grade just below Seconds. 

" Flavor. — Must be reasonably good ; may be strong on tops 
and sides. 

'' Body.— Fair boring, if creamery or dairy, and at least 50% 
boring a full trier, if factory or renovated. 

" Color. — May be irregular. 

" Salt. — High, light, or irregular. 



JUDGING AND GRADING BUTTER. 295 

" Package. — Fairly uniform. 

" Score. — Shall average 75 points, or higher. 

" Fourths. 

" Shall be a grade just below Thirds, and may consist of 
promiscuous lots. 

" Flavor.— May be off-flavored, and strong on tops and sides. 

" Body. — Not required to draw a full trier. 

" Color. — May be irregular. 

" Salt. — High, light, or irregular. 

" Package. — Any kind of package mentioned at time of sale. 



" Packing Stock. 

"No. 1. Shall be original butter without the addition of 
moisture, or salt, sweet, and sound, packed in large, new barrels, 
having a wooden head in each end, or in new tubs, both to 
be parchment-paper lined, or a good, uniform second-hand 
barrel, having a wooden head in each end and parchment- 
paper lined. Barrels and tubs to be packed full. 

''No. 2. Shall be original butter, without the addition of 
salt or water, sweet and sound, and can be packed in pro- 
miscuous or different kinds of barrels, tubes, or tierces, without 
being parchment-paper lined, and may be packed in either 
two-headed or cloth-covered barrels. 

" No. 3. Shall be of any grade or quality above grease, and 
packed in any and all kinds of packages. 

" Charges for inspection shall be the same as the rules call 
for on other grades. 

" Grease. 

" Shall consist of all grades of butter below Fourths, free 
from adulterations. 

" Parties wishing to offer butter not described in the fore- 
going classifications and grades must specify its character. 



296 



BUTTER-MAKING. 



" Packages. 

" Must be sound, with full number of hoops covers tight, 
and properly fastened, or made so at the seller's expense, 
unless otherwise stipulated at the time of sale." 

Export Butter. 

The observations of the authors have been that the reputa- 
tion of the American butter is not all that is desirable on the 




Fig. 172. — Shipping Russian butter from Siberia. (U. S. Govt. Bui.) 

English market. Some American butter is good enough to 
sell on an equality with Danish butter, and in some instances 
it is palmed off for such. Much poor butter, however, has been 
allowed to go onto the English market, and this has in some 
measure ruined the reputation of our butter. 

Butter for export purposes should be of the very best, and 
made in such a way as to insure good keeping qualities. 

The standing of the different kinds of butter, as observed 
on the English market, were as follows: 



JUDGING AND GRADING BUTTER. 297 

(1) Fresh French Rolls. 

(2) Danish Creamery. 

(3) Irish Creamery. 

(4) New Zealand. 

(5) Canadian, Australian, Argentine, United States, and 
Siberia. 

For Storage Purposes. 

(1) Danish. 

(2) New Zealand. 

(3) Siberia. 



APPENDIX. 



LABORATORY COURSE IN FARM DAIRYING, 
IOWA DAIRY SCHOOL. 

General Suggestions. 

Products and utensils needed in the work will be furnished. 
When the work is completed the separators and the utensils 
should be properly cleaned, and then put away in their respec- 
tive places. 

To properly clean a separator take it apart and wash all 
the milky portions with a brush and warm water containing a. 
little washing-powder. Then rinse it in clean scalding-hot 
water and set aside to drain and dry. This method of cleaning 
applies to all tin utensils. Be careful not to bend or dent any/ 
of the parts belonging to the separator. 

Before starting the separator see that it is properly put 
together and well oiled. Do not turn the machine at an ex- 
cessive speed. 

All students are required to wear clean, white suits. 

The work is of such a nature that it requires the attention 
of the students until it is completed. If more than three hours 
is needed for completing it, students will receive credit for 
extra time. 

Have with you a copy of "Separator Directions" for refer- 
ence. 

29a 



300 



APPENDIX 



Date. 



Exercise No. 1. 

1. Separate a canful of milk at 85° F. on three different 
separators. 

2. Sample cream and skimmed milk from each, and test 
it for fat. 

Report Results. 





Per Cent Fat in 
Whole Milk. 


Per Cent Fat in 
Skim-milk. 


Per Cent Fat in 
Cream. 


No. 1 








Name 








No. 2 








Name 








No. 3 








Name 









Remarks : 



Signed 



LABORATORY COURSE IN FARM DAIRYING. 



301 



Date. 



Exercise No. 2. 

To determine effect of variation in speed upon thickness 
of cream, upon fat left in skimmed milk, and upon capacity of 
separator, 

1. Separate a half canful of milk at half speed. (Weigh 
milk first.) Take a sample of the cream and skimmed milk to 
be tested for fat. 

2. Separate a half canful of milk at full speed. (See 
directions.) Take a sample of the cream and skimmed milk 
to be tested for fat. 

3. Test the above samples for fat. 

4. When the above samples are taken, watch the time and 
determine the capacity of the machine at half speed and full 
speed. 

Report Results. 





Per Cent Fat 

in Whole 

Milk. 


Per Cent Fat 
in Skim- 
milk. 


Per Cent Fat 
in Cream. 


Capacity of 
Separator 
per Hour. 


Name of 
Separator. 


Half speed 












Full speed 












Total fat 






- 






Total fat lost 
in bowl 













Remarks: 



Signed. 



302 



APPENDIX. 



Date. 



Exercise. No. 3. 

To determine the effect of a variation of temperature upon 
thickness of cream, fat left in skimmed milk, and upon capacity 
of separators. 

1. Temper three lots of milk: No. 1 to 60° F., No. 2 to 
90° F., and No. 3 to 120° F., and separate at the respective 
temperatures. 

2. Sample and test cream and skimmed milk for fat. 

3. Determine capacity of machine at different temperatures 
as in previous exercise. 

Report Results. 





Per Cent Fat 

in Whole 

Milk. 


Per Cent Fat 
in Skim- 
milk. 


Per Cent Fat 
in Cream. 


Capacity per 
Hour. 


Name of 
Separator. 


Separated at 
60° F. 












Separated at 
90° F. 












Separated at 
120° F. 






! 






Total fat 








1 
i 




Total fat in 
bowl 













Remarks : 



Signed. 



LABORATORY COURSE IN FARM DAIRYING. 



303 



Date. 



Exercise No 4. 

To determine effect of variation of inflow upon complete- 
ness of separation, upon richness of cream, and upon fat left in 
skimmed milk. 

1. Separate a quantity of milk, and turn faucet so as to 
allow the maximum amount of inflow. Take a sample of cream 
and skimmed milk and test for fat. 

2. Shut off the inflow a trifle. Take another sample of 
cream and skimmed milk and test for fat. 

3. Shut off inflow still more. Take sample of milk and 
cream again and test for fat. 



Report Results. 





Per Cent Fat 
in Whole Milk. 


Per Cent Fat 
in Skim-milk. 


Per Cent Fat 
in Cream. 


Name of 
Separator. 


No. 1. Full inflow 










No. 2. Inflow 
closed a trifle 










No. 3. Inflow 
closed considerably 










Remarks :...... 





Signed. 



304 



APPENDIX. 



Date. 



Exercise No. 5. 

To determine effect of diluting whole milk with water, upon 
thickness of cream and completeness of separation by the dilu- 
tion method of separation (hydraulic). 

1. Mix some milk containing a definite percentage of fat. 
Pour an equal amount into two shot-gun cans, and number 
them 1 and 2. Do not fill them full. Allow enough space so 
that 25% of water can be added to can No. 2. 

2. The cream should be left to raise at the same tempera- 
ture. 

3. Test cream and skim-milk for fat by the Babcock method. 



Report Results. 





Separation 
Temp. 


Per Cent 
Fat in 
Cream. 


Per Cent 

Fat in 
Skim-milk. 


Pounds Fat 

Lost in 
Skim-milk. 


Time for 
Separation. 


Quality 
Cream. 


Nol 
Cooley 














No. 2 
Hydraulic 














Remarks 





Signed. 



LABORATORY COURSE IN FARM DAIRYING. 



305 



Date. 



Exercise No. 6. 

To determine effect of high and low temperature upon 
thickness of cream and completeness of separation by the deep- 
setting gravity system (Cooley). 

1. Mix thoroughly some whole milk containing a definite 
per cent of fat. Fill two clean shot-gun cans with it and num- 
ber them 1 and 2 respectively. 

2. Cool to, and keep No. 1 at a low temperature (about 
50° F.) for at least 24 hours. No. 1 should be kept at a tem- 
perature of about 60° F. to 70° F. the same length of time. 

3. Skim both canfuls of milk. Test the cream and skim- 
milk from each for butter-fat. 



Report Results. 





Skimming 
Temperature. 


Per Cent Fat 
in Cream. 


Per Cent Fat 
in Skim-milk. 


Time for 
Separation. 


No. 1 
Low Temperature 










No. 2 
High Temperature 










Remarks 





Signed. 



306 



APPENDIX. 



Date 



EXEKCISE No. 7. 

To determine effects of cream-ripening on quality of butter. 

1. Divide a certain weight of cream, containing a definite 
percentage of fat, into two parts (1 and 2). Cool No. 1 to aboui 
50° F. Ripen No. 2 to the proper acidity and cool to about 
50° F. 

2. Test both lots for acidity. 

3. Churn the two lots of cream, wash, work, and salt alike, 
and note the difference in the two lots of butter. 

4. Test the buttermilk for fat. 

Report Results. 





Per Cent 
Acidity. 


Pounds of 
% 
Cream. 


Pounds of 
Fat. 


Pounds of 
Butter. 


Per Cent 
Overrun. 


Per Cent 

Fat in 

Buttermilk 


No. 1 

Sweet 














No. 2 
Ripe 















Remarks. 



Signed. 



LABORATORY COURSE IN FARM DAIRYING. 



307 



Date. 



Exercise No. 8. 

To determine the effects of high and low churning tempera- 
tures. 

1. Divide a definite number of pounds of ripened cream, con- 
taining a certain percentage of fat, into two lots (Nos. 1 and 2). 

2. Churn No. 1 at about 52° F. 

3. Churn No. 2 at about 60° F. 

4. Test the buttermilk for fat. Color, wash, work, and 
salt alike. 

Report Results. 





Per Cent 
Acidity. 


Pounds of 
Cream. 


Pounds of 
Fat. 


Pounds of 
Butter. 


Per Cent 
Overrun. 


Per Cent 

Fat in 

Buttermilk 


No. 1 
Low Tem- 
perature. 














No. 2 
High Tem- 
perature. 










• 





Remarks. 



Signed. 



308 



APPENDIX. 



Date. 



Exercise No. 9. 

To determine effects of duration of temperature. 

1. Divide a definite number of pounds of ripened cream^ 
containing a definite percentage of fat, into two lots (Nos. 1 
and 2). 

2. Cool No. 1 to 50° F.^ and let stand at least three hours. 
(Preferably overnight.) 

3. Cool No. 2 to 50° F., and churn at once. 

The two lots should be churned at the same temperature. 

Report Results. 





Per Cent 
Acidity. 


Pounds of 
% 
Cream. 


Pounds of 
Fat. 


Pounds of 
Butter. 


Per Cent 
Overrim. 


Per Cent 

Fat in 
Butternailk 


No. 1 
Cooled a 
long time 














No. 2 

Cooled a 

short time 














Remarks 





Signed. 



LABORATORY COURSE IN FARM DAIRYING. 



309 



Date. 



Exercise No. 10. 

To determine effects of pasteurization upon butter. 

1. Divide a definite number of pounds of sweet cream, 
containing a definite per cent of fat, into two lots (1 and 2). 

2. Pasteurize No. 1 to about 175° F., by putting the can 
containing the cream into hot water. Ripen and cool to 50° F., 
and allow to stand at least three hours before churning. 

3. Ripen No. 2; cool to 50° F., and churn. 

Note the difference in quality of the two lots of butter. 

Report Results. 





Per Cent 

Acidity. 


Pounds of 
% 
Cream. 


Pounds of 
Fat. 


Pounds of 
Butter. 


Per Cent 
Overrun. 


Per Cent 

Fat in 

Buttermilk 


No. 1 
Pasteurized 














No. 2 
Unpas- 
teurized 















Remarks. 



Signed. 



310 



APPENDIX. 



Date. 



Exercise No. 11. 

To determine effect of percentage fat in cream upon quick- 
ness and completeness of churning, and also upon conditions of 
butter. 

1. Take two lots of ripened cream. Number thin cream 1, 
and thick cream 2. 

Ripen both lots of cream to proper degree of acidity, and 
temper to the same churning temperature. 

2. Note the time it takes to churn each lot. Also note the 
condition of the butter when it ''breaks." 

3. Test the buttermilk for fat. 

Report Results. 





Per Cent 
Acidity. 


Pounds of 
Cream. 


Pounds of 

Fat. 


Pounds of 
Butter. 


Per Cent 
Overrun. 


Per Cent 

Fat in 

Buttermilk 


No. 1 
Thin cream 














No. 2 
Thick cream 















Remarks. 



Signed. 



LABORATORY COURSE IN FARM DAIRYING. 311 

Date 

Exercise No. 12. 

Fermentation test. 

1. Take three pint-jars and clean them thoroughly. Num- 
ber them 1, 2, and 3. 

2. Half fill Nos. 1 and 2 with the same kind of milk; add 
a little pinch of manure or dirt to No. 1. Let them stand at a 
temperature of about 90° F. and closely note the changes that 
take place. To No. 3 add a different kind of milk, and let it 
ferment under the same conditions as above. 

Note the difference in taste, smell, and appearance when they 
have coagulated. 

Remarks 



No. 1 
Dirt added 



No. 2 



No. 3 



Signed. 



312 



APPENDIX. 



Date. 



Exercise No. 13. 

To determine effect of uneven distribution of salt upon 
butter. 

1. Churn a certain amount of ripened cream containing a 
definite per cent of fat. 

2. Divide the butter into two lots (1 and 2). To No. 1 
add salt the same as usual, but do not work the butter so much. 

3. Do not add any salt to No. 2. 

4. Pack in separate tubs and let stand over night, then 
closely examine both the lots of butter and report your observa- 
tions. 





Per Cent 

Acidity. 


Pounds of 
% 
Cream. 


Pounds of 
Fat. 


Pounds of 
Butter. 


Per Cent 
Overrun. 


Per Cent 

Fat in 

Buttermilk 


No. 2 
Salted 














No. 2 
Unsalted 















Remarks. 



Signed. 



LABORATORY COURSE IN FARM DAIRYING. 313 



Date. 



Exercise No. 14. 

The determine effect of length of time cream is kept upon 
quality of butter. 

1. Skim a definite amount of c.ream and keep it in cold 
water one week. Then churn and note quahty of butter. 

2. Skim about an equal quantity of cream on the same sepa- 
rator. Have all conditions as near alike as possible in order 
to obtain same thickness of cream and otherwise comparative 
results. Ripen and churn this while the cream is fresh. 

3. Compare results with No. 1. 



Report Results. 





Age of Cream. 


Per Cent Fat 
in Buttermilk. 


Quality of Butter. 


No. 1 
Old cream 








No. 2 
Fresh cream 








Remarks 





Signed. 



314 APPENDIX. 



LEGAL STANDARDS FOR MILK— DAIRY LAWS* 

The following States and Territories, viz., Alabama, Arizona, 
Arkansas, California, Colorado, Delaware, Florida, Louisiana, 
Mississippi, Missouri, Montana, North Dakota, Texas, and 
Wyoming, have established no legal standard. 

The Dominion of Canada, Connecticut, Idaho, Illinois, 
Indiana, Kansas, Kentucky, Maryland, Nebraska, Nevada, 
New Mexico, North Carohna, Oklahoma, South Dakota, Ten- 
nessee, Utah, Virginia, and West Virginia have general laws 
prohibiting dilution, skimming, or other adulteration. 

In other States the percentage standards are as follows: 

Specific Total -ito+o 

Gravity. Solids. ■*'^^®- 

Per Cent. 

District of Columbia 12.5 3.5 

Georgia 12 3.5 

Iowa 12.5 3 

Maine 12 3 

Massachusetts (Apr. to Aug., inclusive) 12 3 

(Sept. to Mar. " ) 13 3.7 

Michigan 1.029-1.033 12.5 3 

Minnesota 13 3.5 

New Hampshire , 13 ... 

New Jersey 12 ... 

New York 12 3 

Ohio (May and June) 11.5 

' ' (July to April, inclusive) 12 3 

Oregon 12 3 

Pennsylvaniat 1.029-1.033 12.5 3 

Rhode Island 12 2.5 

South Carolina 11.5 3 

Vermont (May and June) 12 

' ' (July to April, inclusive) 12.5 

Washington 11 3 

Wisconsin 3 

* From Wing in " Milk and Its Products." 

t Applies only to cities of the second and third classes. 



METRIC SYSTEM. 315 



METRIC SYSTEM * 

METRIC SYSTEM OF WEIGHTS AND MEASURES AND TABLES 
FOR THE CONVERSION OF METRIC WEIGHTS AND MEAS- 
URES INTO CUSTOMARY UNITED STATES EQUIVALENTS 
AND THE REVERSE. 

In the metric system the meter is the base of all the weights 
and measures which it employs. 

The meter was intended to be, and is very nearly, one ten- 
millionth part of the distance measured on a meridian of the 
earth from the equator to the pole, and equals about 39.37 
inches or nearly 3 feet 3f inches. 

The meter is the primary unit of length. 

Upon the meter are based the following primary units : the 
square meter, the are, the cubic meter or stere, the liter, and 
the gram. 

The square meter is the unit of measure for small surfaces; 
as the surface of a floor, table, etc. 

The are is the unit of land measure; this is a square whose 
side is 10 meters in length, and which contains 100 square 
meters. 

The cubic meter or stere is the unit of volume; this is a 
cube whose edge is 1 meter in length. 

The liter is the unit of capacity; tliis is the capacity of a 
cube whose edge is one-tenth of a meter in length. 

The gram is the unit of weight; this is the weight of dis- 
tilled water contained in a cube whose edge is the one-hundredth 
part of a meter; a gram is therefore the one-thousandth part 
of a kilogram, and the one-millionth part of a metric ton. 



* From The American Chamber of Commerce. 



316 



APPENDIX. 



Measures of Length. 



Metric Denominations and Values. 


Equivalents in Denominations in Use. 


Myriameter 

Kilometer 

Hectometer 

Dekameter 

Meter 

Decimeter 

Centimeter 

Millimeter 


10,000 meters 
1,000 meters 
100 meters 
10 meters 
1 meter 
. 1 meter 
.01 meter 
.001 meter 


6.2137 miles 
.62137 mile, or 3,280 ft. 10 in. 
328 feet 1 inch 
393 . 7 inches 
39 . 37 inches 
3 . 937 inches 
.3937 inch 
.0394 inch 



Measures of Surface. 



Metric Denominations and Values. 


Equivalents in Denominations 
in Use. 


Hectare 

Are 


10,000 square meters 
100 square meters 
1 square meter 


2.471 acres 
119.6 square yards 
1,550 square inches 


Centare 



Measures of Capacity. 



Metric Denominations and Values. 


Equivalents in Denominations 
in Use. 


Names. 


No. of 
Liters. 


Cubic Measure. 


Dry Measure. 


Liquid or Wine 
Measure. 


Kiloliter \ 

or stere. . / 

Hectoliter. . 

Dekaliter. . . 

Liter 

Deciliter. . . . 
Centiliter. . . 
Milliliter. . . . 


1,000 

100 
10 

1 

.1 

.01 
.001 


1 cubic meter 

.1 cubic meter 
10 cu. decimeters 

1 cu. decimeter 
.1 cu. decimeter 
10 cu. centimeters 

1 cu. centimeter 


1.308 cu. yds. 

2 bush. 3.35 pks. 
9.08 quarts 

.908 quart 
6.1022 cu. ins. 

.6102 cu. in. 

.061 cu. in. 


264.17 gals. 

26.417 gals. 

2.6417 gals. 

1.0567 qts. 

.845 gill 

.338fl.oz. 

.27fl.dram 



METRIC SYSTEM. 



317 



Weights. 



Metric Denominations and Values. 


Equivalents in Deno- 
minations in Use. 


Names. 


Number of 
Grams. 


Weight of What 

Quantity of Water at 

Maximum Density. 


Avoirdupois Weight. 


Metric ton 


1,000,000 

100,000 

10,000 

1,000 

100 

10 

1 
.1 

.01 
.001 


1 cubic meter 

1 hectoliter 

1 dekaliter 

1 liter 

1 deciliter 
10 cubic centimeters 

1 cubic centimeter 
.1 cubic centimeter 
10 cubic millimeters 

1 cubic millimeter 


2204.6 pounds 
220.46 pounds 
22.046 pounds 
2.2046 pounds 
3.5274 ounces 
.3527 ounce 


Quintal 


Myriagram 

Kilogram or kilo. . . . 

Hectogram 

Dekagram 


Gram 

Decigram 

Centigram 


15.432 grains 
1.5432 grains 
.1543 grain 
.0154 grain 


Milligram 







Common Measures and Weights, with their Metric Equivalents. 

The following are some of the Measures in common use, with their equiva- 
lents in measures of the Metric System: 



Common 
Measures. 



1 inch 

1 foot 

1 yard 

1 rod 

1 mile 

1 square inch 

1 square foot 

1 square yard 

1 square rod 

1 acre 

1 square mile 

1 cubic inch 

1 cubic foot 

1 cubic yard 



Equivalents 



2.54 centimeters 
.3048 meter 
.9144 meter 
5.029 meters 
1.6093 kilometers 
6.452 sq. centimeters 
.0929 sq. meter 
.8361 sq. meter 
25.29 sq. meters 
.4047 hectare 
259 hectares 
16.39 cu. centimeters 
.02832 cu. meter 
.7646 cu. meter 



Common Measures 



1 cord 

1 liquid quart 

1 gallon 

1 dry quart 

1 peck 

1 bushel 

1 ounce av'd'p 

1 pound av'd'p 

1 ton (2000 lbs.) 

1 ton (2240 lbs.) 

1 grain troy 

1 ounce troy 

1 pound troy 



Equivalents. 



3.624 steres 
.9465 liter 
3.86 liters 
1.101 liters 
8.811 liters 
35.24 liters 
28.35 grams 
.4536 kilogram 
.9072 metric ton 
1.016 metric ton 
.0648 gram 
31.104 grams 
.3732 kilogram 



318 



APPENDIX. 



Table for the Conversion of Metric Weights and Measures into Cus- 
tomary United States Equivalents and the Reverse. 

From the legal equivalents are deduced the following tables for convert- 
ing United States weights and measures. 

metric to customary. 
Linear Measure. 



Meters = Inches. 


Meters = Feet. 


Meters = Yards. 


Kilometers = Miles. 


1= 39.37 


1= 3.28087 


1 = 1.093623 


1=0.62137 


2= 78.74 


2= 6.56174 


2 = 2.187246 


2 = 1. 24274 


3 = 118.11 


3= 9.84261 


3=3.280869 


3 = 1.86411 


4 = 157.48 


4 = 13.12348 


4 = 4.374492 


4 = 2.48548 


5 = 196.85 


5 = 16.40435 


5 = 5.468175 


5 = 3.10685 


6 = 236.22 


6 = 19.68522 


6 = 6.561738 


6 = 3.72822 


7 = 275.59 


7 = 22.96609 


7 = 7.655361 


7 = 4.34959 


8 = 314.96 


8 = 26 . 24696 


8 = 8.748984 


8 = 4.97096 


9 = 354.33 


9 = 29 . 52783 


9 = 9.842607 


9 = 5.59233 



CUSTOMARY TO METRIC. 
Linear Measure. 



Inches = Centimeters. 


Feet = Meters. 


Meters = Yards. 


Miles = Kilometers. 


1= 2.54 


1=0.304798 


1=0.914393 


1=1. 60935 


2= 5.08 


2 = 0.609596 


2 = 1.828787 


2= 3.21869 


3= 7.62 


3 = 0.914393 


3 = 2.743179 


3= 4.82804 


4 = 10.16 


4 = 1.219191 


4 = 3.657574 


4= 6.43739 


5 = 12.70 


5 = 1.523989 


5 = 4.571966 


5= 8.04674 


6 = 15.24 


6 = 1.828787 


6 = 5.486358 


6= 9.65608 


7 = 17.78 


7 = 2.133584 


7 = 6.400753 


7 = 11.26543 


8 = 20.32 


8 = 2.438382 


8 = 7.315148 


8 = 12.87478 


9 = 22.86 


9 = 2.743179 


9 = 8.229537 


9 = 14.48412 



METRIC SYSTEM. 



319 



Square Measure. 



Cubic Measure. 



Square Cen- 
timeters 

11 
Square 
Inches. 


Square 
Meters 
II 

Square 
Feet. 






Cubic 
Meters 

Cubic 
Feet. 


Cubic 

Feet 
II 
Cubic 

Meters. 


1=0.155 


1=10.764 


1 = 


1.196 


1= 35.315 


1=0.02832 


2 = 0.310 


2 = 21 . 528 


2 = 


2.392 


2= 70.031 


2 = 0.05663 


3 = 0.465 


3=32.292 


3 = 


3.588 


3 = 105.947 


3=0.08495 


4 = 0.620 


4 = 43.055 


4 = 


4.784 


4 = 141.262 


4 = 0.11326 


5 = 0.775 


5 = 53.819 


5 = 


5.980 


5 = 176.584 


5 = 0.1415S 


6 = 0.930 


6 = 64.583 


6 = 


7.176 


6 = 210.899 


6 = 0.16990 


7 = 1.085 


7 = 75.347 


7 = 


8.372 


7 = 247.209 


7 = 0.19821 


8 = 1 . 240 


8=86.111 


8 = 


9.568 


8 = 282.525 


8 = 0.22653 


9 = 1.395 


9 = 96.874 


9 = 


10.764 


9 = 317.840 


9 = 0.25484 



Square Measure. 



Liquid Measure. 



Square 
Inches 

11 
Square Cen- 
timeters. 


Square 

Feet 

11 

Square 

Meters. 


Square 
Yards 

II 
Square 
Meters. 


Centimeters 

II 
Fluid 
Ounces. 


Liters 
11 
Quarts. 


Liters 
II 
Gallons. 


1= 6.452 


1=0.09290 


1=0.836 


1=0.338 


1=1.0567 


1=0.26417 


2 = 12.903 


2 = 0.18581 


2 = 1.672 


2 = 0.676 


2 = 2.1134 


2 = 0.52834 


3 = 19.354 


3=0.27871 


3 = 2.508 


3 = 1.014 


3=3.1700 


3=0.79251 


4 = 25.806 


4 = 0.37161 


4 = 3.344 


4 = 1.352 


4 = 4.2267 


4 = 1.05668 


5 = 32.257 


5 = 0.46452 


5 = 4.181 


5 = 1.691 


5 = 5.2834 


5 = 1.32085 


6 = 38.709 


6 = 0.55742 


6 = 5.017 


6 = 2.029 


6 = 6.3401 


6 = 1. 58502 


7 = 45.160 


7 = 0.65032 


7 = 5.853 


7 = 2.368 


7 = 7.3968 


7 = 1.84919 


8 = 51.612 


8 = 0.74323 


8 = 6.689 


8 = 2.706 


8 = 8.4534 


8 = 2.11336 


9 = 58.063 


9 = 0.83613 


9 = 7.525 


9 = 3.043 


9 = 9.5101 


9 = 2. 3775a 



Dry Measure. 



Liquid Measure. 



Hectoliters 
Bushels. 


Bushels 

11 

HectoUters. 


1= 2.8375 


1=0.35242 


2= 5.6750 


2 = 0.70485 


3= 8.5125 


3 = 1.05727 


4 = 11.3500 


4 = 1.40969 


5 = 14.1875 


5 = 1.76211 


6 = 17.0250 


6 = 2.11454 


7 = 19.8625 


7 = 2.46696 


8 = 22.7000 


8 = 2.81938 


9 = 25.5375 


9 = 3.17181 



O = n: 




1= 2.957 
2= 5.915 
3= 8.872 

4 = 11.830 

5 = 14.787 

6 = 17.744 

7 = 20 . 702 

8 = 23 . 659 

9 = 26.616 



1=0.94636 

2 = 1.89272 

3 = 2.83908 

4 = 3.38544 

5 = 4.33180 



6 = 5. 

7 = 6. 

8 = 7. 

9 = 8. 



67816 
62452 
57088 
51724 



= o 

3 



= 3.78544 

= 7.57088 
=11.35632 
=15.14176 
=18.92720 
=22.71264 
=26.49808 
=30.28352 
=34.06896 



320 



APPENDIX. 

Weight (Avoirdupois). 



Centi- 
grams 

II 
Grains. 


Kilograms 

II 

Oounces 
Avoirdu- 
pois. 


Kilograms 

II 

Pounds 
Avoirdu 
pois. 


Metric 
Tons. 

11 

Long 
Tons. 


1=0.1543 


1=735.274 


1= 2.20462 


1=0.9842 


2=0.3086 


2= 70.548 


2= 4.40924 


2 = 1.9684 


3 = 0.4630 


3 = 105.822 


3= 6.61386 


3 = 2. 9526 


4 = 0.6173 


4 = 141.098 


4= 8.81849 


4 = 3.9368 


5 = 0.7716 


5 = 176.370 


5 = 11.02311 


5 = 4.9210 


6 = 0.9259 


6 = 21 1 . 644 


6 = 13.22773 


6 = 5.9052 


7 = 1.0803 


7 = 246.918 


7 = 15.43235 


7 = 6.8894 


8 = 1. 2346 


8 = 282.192 


8 = 17.63697 


8 = 7.8736 


9 = 1.3889 


9 = 317.466 


9 = 19.84159 


9 = 8.8578 



Grains 

li 

Centi- 
grams. 


Ounces 
Avoirdu- 
pois 

II 

Grams. 


Pounds 
Avoirdu- 
pois 

Kilograms. 


Long 
Tons 

Metric 
Tons. 


1= 6.4799 


1= 28.3495 


1=0.45359 


1=1.0161 


2 = 12.9598 


2= 56.6991 


2 = 0.90919 


2 = 2.0321 


3 = 19.4397 


3= 85.0486 


3 = 1.36078 


3 = 3.0482 


4 = 25.9196 


4 = 113.3981 


4 = 1.81437 


4 = 4.0642 


5 = 32.3995 


5 = 141.7476 


5 = 2.26798 


5 = 5.0803 


6 = 38.8793 


6 = 170.0972 


6 = 2.72156 


6 = 6.0963 


7 = 45.3592 


7 = 198.4467 


7 = 3.17515 


7 = 7.1124 


8 = 51.8391 


- 8 = 226 . 7962 


8 = 3.82874 


8 = 8.1284 


9 = 58.3190 


9 = 255.1457 


9 = 4.08233 


9 = 9 1445 



INDEX. 



PAGE 

Abnormal milk 54 

Acid, butyric, capric, caprylic, myristic, oleic, palmitic, stearic 14 

carbonic, hydrochloric, phosphoric, sulphuric 18 

citric 20 

lactic 213 

salicylic 99 

sulphuric 85 

tests 80, 208, 206 

Acidity of milk 78 

of ripened cream in relation to richness of cream 209 

of starters 223 

tests for 208 

Adhesion of milk 37 

Albumen in milk 16 

Albuminoids in milk 14 

Alkali of various strengths for measuring acid in milk and cream 80 

Amphoteric reaction of milk 32 

Antiseptics 48 

Babcock test for fat 84 

causes and remedies for common defects in clear- 
ness of fat in 87 

Bacteria in milk, aroma and flavor producing 187 

as a cause of deterioration of butter 11 

classification of 50 

conditions favoring development of 45 

desirable and undesirable in cream ripening 189 

number of, in milk 51 

size and shape of 45 

sources of 52 

unfavorable conditions for 48 

Biological changes in ripening cream 210 

Breeds, composition of milk from various 68 

321 



322 INDEX 



PAGBi 



Brine, salting butter with 264 

soaking tubs in 271 

Butter, appearance of 292 

color of 238, 291 

composition of 281 

cost of manufacturing 278 

classification and grades of, as outlined by N. Y. Mercantile Ex- 
change 292 

exportation of 296 

flavor of 290 

judging and grading of 286 

keeping in creameries 276 

making of, on farm 169 

mottled, causes and remedy 263 

packing of 271 , 275 

printing of 274 

rancid, and cause of 11 

saltiness of 292 

storing in creameries 276 

texture or body of 290 

test for water in 87 

washing, and kind of wash-water 247 

w^orking of 266 

Buttermilk 227, 232, 247 

Butyrin 13 

Calculation of amount of salt to add to butter. . 256 

of average per cent fat 105 

of churn yield 109 

of cream-raising coefficient 113 

of dividends 109 

of overrun 107 

of solids in milk 35 

Cans, starter 225 

Care of cream on farm 1 58 

Casein in milk, condition of 15 

Centrifugal separation of cream 129 

Changes in milk and cream, chemical, physical, and biological 210 

Chemical changes in ripe and over-ripe cream 213, 215 

Churn, keeping in good condition 245 

Churn yield, calculation of 109 

Churned milk, sampling 96 

Churning, amount of cream for a 233 

conditions affecting 227 

definition of 226 

difficult, causes and remedy for 243 



INDEX. 323 

PAGE 

Churning mixed, sweet, and sour cream 243 

nature of agitation for 235 

richness of cream for 231 

straining of cream previous to 238 

when to stop. 239 

Citric acid in milk 20 

Color, butter 238 

Coloring matter in milk 20, 31 

Composite samples 99 

care and arrangement of 102 

preservatives for 99 

sampling apparatus for. . 94 

Composition of butter 281 

of colostrum milk 54 

of dairy salts 262 

of different kinds of milk 2 

effect of, on quality of butter 281 

of salty milk 55 

of separator slime 144 

of tuberculous milk 62 

Commercial starters 217 

preparation and use of 218 

Continuous method of pasteurization 173 

"Cooley" method of cream separation 124 

Cows, average production of 66 

breeds of 68 

cost of keeping 66 

table showing profit and loss in keeping 67 

Cream, acidity of, for churning 205 

care of, on farm 158 

effect of cleanliness on quality of 159 

grading of 79 

methods of disposing of 167 

mixing of different cjualities 202 

pasteurization of 173 

of sour 180 

richness of 137, 152 

ripening of 187 

sampling of 93 

specific heat of . . , 38 

Creamery sewage disposal 278 

plans 276 

Deep-setting system of cream separation 124 

Difficult churning, causes and remedy 243 

Dilution, effect of, on creaming 128 



324 INDEX. 

PAGE 

Disinfectants 48, 99, 246 

Electricity, effect of, on germs in milk 53 

Enzymes in milk 20 

effect of heat on 41 

tests for 42 

Exports of butter 296 

Factories, plan of 279 

Farrington's test 208 

Fat in butter 286 

in milk 5 

composition of 13 

condition of 6 

effects of environment 76 

of heat on 42 

of various feeds on composition of 75 

glycerides of 8 

glycerine in 14 

melting-point of 12 

membrane enveloping fat globules 9 

microscopical appearance of 6 

non- volatile 12 

paying for, as compared with fat in cream 116 

separation of 123 

size of globules 7 

testing for 84 

volatile 11 

Feeds, effects on milk 75 

Ferments in milk 44 

classes of 44, 49 

favorable and unfavorable condition for 45, 48 

Fermentations, detection of 56, 81 

various kinds of 44, 55 

Filtration of water 250 

methods and effects of 251 

Flavors of butter 290 

of milk 18, 30, 40 

Food for bacteria 45 

Formula for calculating churn yield 109 

cream-raising coefficient .• . 113 

dividends 109 

overrun 107 

solids in milk 35 

Frozen milk, effects of freezing 96 



INDEX. 325 

PAGE 

Galactase in milk 20 

Gases in milk, eliminating 20, 184 

kinds and sources of 18 

Gerber fermentation test 81 

Glassware for Babcock test 86 

Grading milk and cream 78 

Gravity separation, different systems of 123 

Gritty butter 263 

Heat, effects of, on properties of milk 38, 82 

Heating milk previous to skimming 118 

Hegelund method of milking. 71 

Hydraulic method of separation. 128 

Hydrogen peroxide 42 

Intermittant method of pasteurization 173 

Judging and grading butter 286 

standard for 286 

Keeping property of butter 192 

effect of salt on 258 

Laboratory exercises in farm dairying 299 

Lactation period, effect of, on milk and fat 74 

Lactochrome in milk 20 

Lactometer, comparison of scales on 34 

use of 32 

Lecithin in milk 20 

Lime, its use in creameries 245 

Mammary gland, description of 22 

inflammation of 30 

Mann's test.. 206 

Membrane enveloping fat globules 9 

Mercantile Exchange, N. Y., grades of butter 292 

Metric system of weights and measures 315 

Milk, abnormal 54 

apportioning skimmed 97 

bloody 56 

blue and yellow 54 

classification of 1 

composition 2 

of, from different animals 2 

definition of 1 

effects of thunder-storms on souring of 53 

fat in skimmed 123 



326 INDEX. 

PAGE 

Milk, from barren and spayed cows 61 

grading of 7g 

necessity of good 89 

properties of, physical and chemical 31 

ropy 58 

salty 55 

sampling of 93 

frozen, churned, and sour 22, 96, 97 

secretion of, conditions affecting 28 

theories 25 

specific gravity of 32 

total solids of 3 

tuberculous cows' 62 

variation in quality of, and causes 65 

Milking, frequency of 68 

manner of 70 

Milking-machine 70 

Mottles, causes of, in butter 263 

kinds of 263 

prevention of 264 

Natural starters, preparation of 217 

New York Extras defined 293 

Non-volatile fats 12 

Nuclein in milk 20 

Olein, effect of variation of, on softness of butter 12 

Opacity of milk 31 

Organized ferments 44 

Over-ripe cream 205, 215 

Overrun, definition and calculation of 107 

factors governing 108 

Packing butter, for exhibitions 275 

kind and size of package 270 

preparation of tubs previous to 271 

Palmitin 12 

Pasteurization, advantages of 184 

cost of 183 

definition and methods of 173 

disadvantages of 186 

factors to consider in 175 

of sour cream 180 

use of, direct steam in 1 74 

Pasteurizer, durability and efficiency 175 

Paying for fat in cream as compared with fat in milk 116 



INDEX. 327 

PAGE 

Physical changes in cream 210 

Proteids in milk, as a cause of mottles in butter. „ 264 

kinds of 14 

Quevenne lactometer 33 

Rancid butter, causes of 11 

Receiving milk and cream , . 78 

Richness of cream from centrifugal separator 137 

from gravity separation 125 

Ripening cream, artificial. 199 

kinds of acids produced from. . 214 

natural 198 

purposes of 187 

stirring of cream during 197 

temperature 194 

testing cream for acidity during. 205 

when churned every other day 201 

Salting butter, amount of salt to use 256 

effects of, on keeping property of butter 258 

purpose of 256 

with brine 264 

Salt, as a cause of mottles 263 

composition of American and Danish. , 262 

condition of, when added to butter 261 

effect of, on keeping property of butter 258 

of, on removal of buttermilk 259 

in relation to water in butter 259 

undissolved, in butter 263 

Samples, average. 104 

composite 99 

Sampling-tube 94 

Separation, advantages of centrifugal 129 

centrifugal 129 

classification of centrifugal machines 133 

conditions affecting completeness of 139 

effect of speed as compared with diameter on 143 

factors governing richness of cream 137 

gravity 123 

heating milk for 118 

history and development of 130 

process of centrifugal 134 

results from different methods of 129 

Separator farm, introduction and development in Iowa 146 

reasons for introducing 147 



328 INDEX. 

PAGE 

Separator slime, composition of. 144 

Sewage-disposal plants, cuts of 278 

Score-cards for butter 287 

Shallow-pan creaming 123 

Skimmed milk, apportioning 97 

Standards, legal, for milk 314 

Sterilization 173 

Statements, annual 114 

patrons' monthly 113 

Starter cans 325 

Starters, amount to use 196, 224 

definition, history, and classification 216 

inoculation 220 

length of time to carry 222 

over-ripening and under-ripening of 223 

preparation of. . . 217, 214 

Sugar and curd in butter 282 

in milk 16 

Streaked butter 263 

Table showing amount of acid produced from a definite amount of sugar 

in cream ripening 214 

effect of temperature on growth of bacteria 46 

fat and total solids of milk from various breeds 68 

mmiber of acid- and non-acid-producing germs in ripe 

cream 211 

profits and losses in keeping cows 67 

Taints in milk, eliminating - 19, 40 

sources of 18 

Temperature, churning 227 

duration of 118 

effect of, on bacterial growth 46 

for storing butter 276 

pasteurization 173, 181 

ripening 194 

separation 118 

wash-water 247 

Tests, acid 80 

fat 84 

Tests, fermentation 81 

pasteurized milk 42 

Total solids of milk, variation of 3 

Tubs, preparation and kinds of 271 

Udder, external appearance of 29" 

internal structure of 22 



INDEX. 329 

PAGE 

Unorganized ferments 44 

Urea in milk 20 

Utensils, cleaning 145, 159 

Variation of fat in milk, causes of 63 

Viscogen, use of 39 

Viscosity of milk 37 

restoration of 39 

Volatile fats 11 

Washing butter, kind of wash-water for 248 

purpose of 247 

Water in butter 241 

condition of 242 

Water, in relation to salt in butter 259 

methods of purifying 250 

Wisconsin curd test 81 

Working of butter, objects and efl^ects of 266 



Since they were first put on the market, years ago, the 

U. S. CREAM SEPARATORS 

have been constantly improved and have always stood before the 
dairy public as pre-eminently the best cream separator in every 
essential point. 

The superiority of their skimming has been repeatedly demon- 
strated, and at the Pan American Exposition in 1901 the U. S. 
established the 

WORLD'S RECORD 
FOR CLEAN SKIMMING, 

by leaving only .0138% butter-fat in 
the skim-milk as the average for 

50 separate^ consecutive runs — 

25% less loss of butter-fat by the 
U. S. than by any competitor. 

At the Lewis and Clark Exposi- 
tion, Portland, Ore., 1905, the U. S. 
Separator lowered this record to 
.0126% as a three days' composite 
test of the separated milk from all 
the cows of all the dairy herds at 
the Exposition. 

U. S. Separators are made by 

a company which for over 32 years 

has devoted itself to manufacturing the highest grade apparatus. 

The U. S. Separator to-day is the result of many years of 

experience and progress. In consequence the U. S, SEPARATORS 

ARE BETTER BUILT 

than any others, and so last much longer and still do the best work. 
Thousands of satisfied users testify to this. 

Write for a handsome catalogue containing some of their letters 
and fully describing the construction of the U. S. SEPARATORS. 

VERMONT FARM MACHINE CO., 

BELLOWS FALLS, VT. 

18 centrally located distributing warehouses throughout U. S. and Canada. 




IOWA DAIRY SEPARATORS 

are built under patents owned by this company. The patents 
cover the broad right to narrow the strata of milk in the 
blue milk zone and to widen the strata toward the center 
of the bowl where the butter fat is denser. The result of 
this form of construction permits the skimming of low-tem- 
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and so controls the currents as to absolutely preclude the 
clogging of the separator bowl. 

To know how close a separator can be made to skim 
under adverse conditions is learned practically only by trying 
out an IOWA MACHINE. It is impossible longer to 
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skimmer the IOWA is in a class by itself 

We will be pleased to furnish an IOWA MACHINE 
for a competing test with any other separator to enable 
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not test them out? We will furnish the IOWA to set in 
against other machines. 

IOWA DAIRY SEPARATOR CO., 

Waterloo, Iowa. 



Da.ir7in^ forTVoflt 

That's what every man is in business for — profit. The 
use of a cream separator is becoming general among pro- 
gressive farmers and dairymen. It is no longer a question of 
whether a cream separator will be a profitable investment, 
but rather "which separator will best meet the requirements 
of the dairyman ? " 

The Cream Harvester sets a Standard of Excellence. 
It is light-running, simple and durable in construction, has 
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Write for one. 



International Harvester Company of America 

(Incorporated) 
CHICAGO, - = ILLINOIS 



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